x86/mm: Apply the section attribute to the variable, not its type

This fixes a compilation error in clang in that a linker section
attribute can't be added to a type:

  arch/x86/mm/mmap.c:34:8: error: '__section__' attribute only applies to functions and global variables struct __read_mostly
  ...

By moving the section attribute to the variable declaration, the
desired effect is achieved.
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1409959005-11479-1-git-send-email-behanw@converseincode.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/mm/mmap.c

@@ -31,7 +31,7 @@
 #include <linux/sched.h>
 #include <asm/elf.h>
 
-struct __read_mostly va_alignment va_align = {
+struct va_alignment __read_mostly va_align = {
 	.flags = -1,
 };