x32: Fix coding style violations in the x32 VDSO code

Move the prototype for x32_setup_additional_pages() to a header file,
and adjust the coding style to match standard.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: H. J. Lu <hjl.tools@gmail.com>
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 83aabea..1e40634 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -331,6 +331,8 @@
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 				       int uses_interp);
+extern int x32_setup_additional_pages(struct linux_binprm *bprm,
+				      int uses_interp);
 
 extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
 #define compat_arch_setup_additional_pages	syscall32_setup_pages