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/irq.h b/include/asm-x86/irq.h
index 1a29257..1e5f290 100644
--- a/include/asm-x86/irq.h
+++ b/include/asm-x86/irq.h
@@ -1,5 +1,5 @@
-#ifndef _ASM_IRQ_H
-#define _ASM_IRQ_H
+#ifndef ASM_X86__IRQ_H
+#define ASM_X86__IRQ_H
 /*
  *	(C) 1992, 1993 Linus Torvalds, (C) 1997 Ingo Molnar
  *
@@ -47,4 +47,4 @@
 /* Interrupt vector management */
 extern DECLARE_BITMAP(used_vectors, NR_VECTORS);
 
-#endif /* _ASM_IRQ_H */
+#endif /* ASM_X86__IRQ_H */