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/posix_types_32.h b/arch/x86/include/asm/posix_types_32.h
index 70cf2bb..f7d9adf 100644
--- a/arch/x86/include/asm/posix_types_32.h
+++ b/arch/x86/include/asm/posix_types_32.h
@@ -1,5 +1,5 @@
-#ifndef ASM_X86__POSIX_TYPES_32_H
-#define ASM_X86__POSIX_TYPES_32_H
+#ifndef _ASM_X86_POSIX_TYPES_32_H
+#define _ASM_X86_POSIX_TYPES_32_H
 
 /*
  * This file is generally used by user-level software, so you need to
@@ -82,4 +82,4 @@
 
 #endif /* defined(__KERNEL__) */
 
-#endif /* ASM_X86__POSIX_TYPES_32_H */
+#endif /* _ASM_X86_POSIX_TYPES_32_H */