x86: Fix ASM_X86__ header guards

Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:

a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/include/asm/mmzone_64.h b/arch/x86/include/asm/mmzone_64.h
index 6480f33..a5b3817 100644
--- a/arch/x86/include/asm/mmzone_64.h
+++ b/arch/x86/include/asm/mmzone_64.h
@@ -1,8 +1,8 @@
 /* K8 NUMA support */
 /* Copyright 2002,2003 by Andi Kleen, SuSE Labs */
 /* 2.5 Version loosely based on the NUMAQ Code by Pat Gaughen. */
-#ifndef ASM_X86__MMZONE_64_H
-#define ASM_X86__MMZONE_64_H
+#ifndef _ASM_X86_MMZONE_64_H
+#define _ASM_X86_MMZONE_64_H
 
 
 #ifdef CONFIG_NUMA
@@ -48,4 +48,4 @@
 #endif
 
 #endif
-#endif /* ASM_X86__MMZONE_64_H */
+#endif /* _ASM_X86_MMZONE_64_H */