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_timer.h b/arch/x86/include/asm/mach-default/mach_timer.h
index a075b46..8537285 100644
--- a/arch/x86/include/asm/mach-default/mach_timer.h
+++ b/arch/x86/include/asm/mach-default/mach_timer.h
@@ -10,8 +10,8 @@
  * directly because of the awkward 8-bit access mechanism of the 82C54
  * device.
  */
-#ifndef _ASM_X86_MACH_DEFAULT__MACH_TIMER_H
-#define _ASM_X86_MACH_DEFAULT__MACH_TIMER_H
+#ifndef _ASM_X86_MACH_DEFAULT_MACH_TIMER_H
+#define _ASM_X86_MACH_DEFAULT_MACH_TIMER_H
 
 #define CALIBRATE_TIME_MSEC 30 /* 30 msecs */
 #define CALIBRATE_LATCH	\
@@ -45,4 +45,4 @@
 	*count_p = count;
 }
 
-#endif /* _ASM_X86_MACH_DEFAULT__MACH_TIMER_H */
+#endif /* _ASM_X86_MACH_DEFAULT_MACH_TIMER_H */