Use consistent/modern code formatting for pointers

The convention used by libjpeg:

    type * variable;

is not very common anymore, because it looks too much like
multiplication.  Some (particularly C++ programmers) prefer to tuck the
pointer symbol against the type:

    type* variable;

to emphasize that a pointer to a type is effectively a new type.
However, this can also be confusing, since defining multiple variables
on the same line would not work properly:

    type* variable1, variable2;  /* Only variable1 is actually a
                                    pointer. */

This commit reformats the entirety of the libjpeg-turbo code base so
that it uses the same code formatting convention for pointers that the
TurboJPEG API code uses:

    type *variable1, *variable2;

This seems to be the most common convention among C programmers, and
it is the convention used by other codec libraries, such as libpng and
libtiff.
diff --git a/jsimddct.h b/jsimddct.h
index aa421fb..b19ab48 100644
--- a/jsimddct.h
+++ b/jsimddct.h
@@ -13,26 +13,26 @@
 EXTERN(int) jsimd_can_convsamp_float (void);
 
 EXTERN(void) jsimd_convsamp (JSAMPARRAY sample_data, JDIMENSION start_col,
-                             DCTELEM * workspace);
+                             DCTELEM *workspace);
 EXTERN(void) jsimd_convsamp_float (JSAMPARRAY sample_data,
                                    JDIMENSION start_col,
-                                   FAST_FLOAT * workspace);
+                                   FAST_FLOAT *workspace);
 
 EXTERN(int) jsimd_can_fdct_islow (void);
 EXTERN(int) jsimd_can_fdct_ifast (void);
 EXTERN(int) jsimd_can_fdct_float (void);
 
-EXTERN(void) jsimd_fdct_islow (DCTELEM * data);
-EXTERN(void) jsimd_fdct_ifast (DCTELEM * data);
-EXTERN(void) jsimd_fdct_float (FAST_FLOAT * data);
+EXTERN(void) jsimd_fdct_islow (DCTELEM *data);
+EXTERN(void) jsimd_fdct_ifast (DCTELEM *data);
+EXTERN(void) jsimd_fdct_float (FAST_FLOAT *data);
 
 EXTERN(int) jsimd_can_quantize (void);
 EXTERN(int) jsimd_can_quantize_float (void);
 
-EXTERN(void) jsimd_quantize (JCOEFPTR coef_block, DCTELEM * divisors,
-                             DCTELEM * workspace);
-EXTERN(void) jsimd_quantize_float (JCOEFPTR coef_block, FAST_FLOAT * divisors,
-                                   FAST_FLOAT * workspace);
+EXTERN(void) jsimd_quantize (JCOEFPTR coef_block, DCTELEM *divisors,
+                             DCTELEM *workspace);
+EXTERN(void) jsimd_quantize_float (JCOEFPTR coef_block, FAST_FLOAT *divisors,
+                                   FAST_FLOAT *workspace);
 
 EXTERN(int) jsimd_can_idct_2x2 (void);
 EXTERN(int) jsimd_can_idct_4x4 (void);
@@ -40,19 +40,19 @@
 EXTERN(int) jsimd_can_idct_12x12 (void);
 
 EXTERN(void) jsimd_idct_2x2 (j_decompress_ptr cinfo,
-                             jpeg_component_info * compptr,
+                             jpeg_component_info *compptr,
                              JCOEFPTR coef_block, JSAMPARRAY output_buf,
                              JDIMENSION output_col);
 EXTERN(void) jsimd_idct_4x4 (j_decompress_ptr cinfo,
-                             jpeg_component_info * compptr,
+                             jpeg_component_info *compptr,
                              JCOEFPTR coef_block, JSAMPARRAY output_buf,
                              JDIMENSION output_col);
 EXTERN(void) jsimd_idct_6x6 (j_decompress_ptr cinfo,
-                             jpeg_component_info * compptr,
+                             jpeg_component_info *compptr,
                              JCOEFPTR coef_block, JSAMPARRAY output_buf,
                              JDIMENSION output_col);
 EXTERN(void) jsimd_idct_12x12 (j_decompress_ptr cinfo,
-                               jpeg_component_info * compptr,
+                               jpeg_component_info *compptr,
                                JCOEFPTR coef_block, JSAMPARRAY output_buf,
                                JDIMENSION output_col);
 
@@ -61,14 +61,14 @@
 EXTERN(int) jsimd_can_idct_float (void);
 
 EXTERN(void) jsimd_idct_islow (j_decompress_ptr cinfo,
-                               jpeg_component_info * compptr,
+                               jpeg_component_info *compptr,
                                JCOEFPTR coef_block, JSAMPARRAY output_buf,
                                JDIMENSION output_col);
 EXTERN(void) jsimd_idct_ifast (j_decompress_ptr cinfo,
-                               jpeg_component_info * compptr,
+                               jpeg_component_info *compptr,
                                JCOEFPTR coef_block, JSAMPARRAY output_buf,
                                JDIMENSION output_col);
 EXTERN(void) jsimd_idct_float (j_decompress_ptr cinfo,
-                               jpeg_component_info * compptr,
+                               jpeg_component_info *compptr,
                                JCOEFPTR coef_block, JSAMPARRAY output_buf,
                                JDIMENSION output_col);