x86: drop double underscores from header guards

Drop double underscores from header guards in arch/x86/include.  They
are used inconsistently, and are not necessary.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/include/asm/mach-default/mach_apic.h b/arch/x86/include/asm/mach-default/mach_apic.h
index 2ad00eb..ff3a6c2 100644
--- a/arch/x86/include/asm/mach-default/mach_apic.h
+++ b/arch/x86/include/asm/mach-default/mach_apic.h
@@ -1,5 +1,5 @@
-#ifndef _ASM_X86_MACH_DEFAULT__MACH_APIC_H
-#define _ASM_X86_MACH_DEFAULT__MACH_APIC_H
+#ifndef _ASM_X86_MACH_DEFAULT_MACH_APIC_H
+#define _ASM_X86_MACH_DEFAULT_MACH_APIC_H
 
 #ifdef CONFIG_X86_LOCAL_APIC
 
@@ -153,4 +153,4 @@
 {
 }
 #endif /* CONFIG_X86_LOCAL_APIC */
-#endif /* _ASM_X86_MACH_DEFAULT__MACH_APIC_H */
+#endif /* _ASM_X86_MACH_DEFAULT_MACH_APIC_H */