x86: consolidate header guards

This patch is the result of an automatic script that consolidates the
format of all the headers in include/asm-x86/.

The format:

1. No leading underscore. Names with leading underscores are reserved.
2. Pathname components are separated by two underscores. So we can
   distinguish between mm_types.h and mm/types.h.
3. Everything except letters and numbers are turned into single
   underscores.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
diff --git a/include/asm-x86/msidef.h b/include/asm-x86/msidef.h
index 296f29c..3139666 100644
--- a/include/asm-x86/msidef.h
+++ b/include/asm-x86/msidef.h
@@ -1,5 +1,5 @@
-#ifndef ASM_MSIDEF_H
-#define ASM_MSIDEF_H
+#ifndef ASM_X86__MSIDEF_H
+#define ASM_X86__MSIDEF_H
 
 /*
  * Constants for Intel APIC based MSI messages.
@@ -48,4 +48,4 @@
 #define  MSI_ADDR_DEST_ID(dest)		(((dest) << MSI_ADDR_DEST_ID_SHIFT) & \
 					 MSI_ADDR_DEST_ID_MASK)
 
-#endif /* ASM_MSIDEF_H */
+#endif /* ASM_X86__MSIDEF_H */