x86: make clear_fixmap() available on 64-bit as well

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/fixmap_64.h b/include/asm-x86/fixmap_64.h
index f3d7685..355d26a 100644
--- a/include/asm-x86/fixmap_64.h
+++ b/include/asm-x86/fixmap_64.h
@@ -8,8 +8,8 @@
  * Copyright (C) 1998 Ingo Molnar
  */
 
-#ifndef _ASM_FIXMAP_H
-#define _ASM_FIXMAP_H
+#ifndef _ASM_FIXMAP_64_H
+#define _ASM_FIXMAP_64_H
 
 #include <linux/kernel.h>
 #include <asm/apicdef.h>