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/olpc.h b/arch/x86/include/asm/olpc.h
index d7328b1..834a302 100644
--- a/arch/x86/include/asm/olpc.h
+++ b/arch/x86/include/asm/olpc.h
@@ -1,7 +1,7 @@
 /* OLPC machine specific definitions */
 
-#ifndef ASM_X86__OLPC_H
-#define ASM_X86__OLPC_H
+#ifndef _ASM_X86_OLPC_H
+#define _ASM_X86_OLPC_H
 
 #include <asm/geode.h>
 
@@ -129,4 +129,4 @@
 #define OLPC_GPIO_LID		geode_gpio(26)
 #define OLPC_GPIO_ECSCI		geode_gpio(27)
 
-#endif /* ASM_X86__OLPC_H */
+#endif /* _ASM_X86_OLPC_H */