Format preprocessor macros more consistently

Within the libjpeg API code, it seems to be more the convention than not
to separate the macro name and value by two or more spaces, which
improves general readability.  Making this consistent across all of
libjpeg-turbo is less about my individual preferences and more about
making it easy to automatically detect variations from our chosen
formatting convention.  I intend to release the script I'm using to
validate this stuff, once it matures and stabilizes a bit.
diff --git a/turbojpeg-jni.c b/turbojpeg-jni.c
index 55d3342..d0ca37d 100644
--- a/turbojpeg-jni.c
+++ b/turbojpeg-jni.c
@@ -37,7 +37,7 @@
 #include "java/org_libjpegturbo_turbojpeg_TJDecompressor.h"
 #include "java/org_libjpegturbo_turbojpeg_TJ.h"
 
-#define PAD(v, p) ((v + (p) - 1) & (~((p) - 1)))
+#define PAD(v, p)  ((v + (p) - 1) & (~((p) - 1)))
 
 #define bailif0(f) { \
   if (!(f) || (*env)->ExceptionCheck(env)) { \
@@ -70,7 +70,7 @@
   goto bailout; \
 }
 
-#define _throwarg(msg) _throw(msg, "java/lang/IllegalArgumentException")
+#define _throwarg(msg)  _throw(msg, "java/lang/IllegalArgumentException")
 
 #define _throwmem() \
   _throw("Memory allocation failure", "java/lang/OutOfMemoryError");
@@ -84,7 +84,7 @@
   handle = (tjhandle)(size_t)(*env)->GetLongField(env, obj, _fid);
 
 #ifdef _WIN32
-#define setenv(envvar, value, dummy) _putenv_s(envvar, value)
+#define setenv(envvar, value, dummy)  _putenv_s(envvar, value)
 #endif
 
 #define prop2env(property, envvar) { \