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/processor-flags.h b/arch/x86/include/asm/processor-flags.h
index dc5f071..7a3e836 100644
--- a/arch/x86/include/asm/processor-flags.h
+++ b/arch/x86/include/asm/processor-flags.h
@@ -1,5 +1,5 @@
-#ifndef ASM_X86__PROCESSOR_FLAGS_H
-#define ASM_X86__PROCESSOR_FLAGS_H
+#ifndef _ASM_X86_PROCESSOR_FLAGS_H
+#define _ASM_X86_PROCESSOR_FLAGS_H
 /* Various flags defined: can be included from assembler. */
 
 /*
@@ -97,4 +97,4 @@
 #endif
 #endif
 
-#endif /* ASM_X86__PROCESSOR_FLAGS_H */
+#endif /* _ASM_X86_PROCESSOR_FLAGS_H */