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/local.h b/arch/x86/include/asm/local.h
index ae91994..47b9b6f 100644
--- a/arch/x86/include/asm/local.h
+++ b/arch/x86/include/asm/local.h
@@ -1,5 +1,5 @@
-#ifndef ASM_X86__LOCAL_H
-#define ASM_X86__LOCAL_H
+#ifndef _ASM_X86_LOCAL_H
+#define _ASM_X86_LOCAL_H
 
 #include <linux/percpu.h>
 
@@ -232,4 +232,4 @@
 #define __cpu_local_add(i, l)	cpu_local_add((i), (l))
 #define __cpu_local_sub(i, l)	cpu_local_sub((i), (l))
 
-#endif /* ASM_X86__LOCAL_H */
+#endif /* _ASM_X86_LOCAL_H */