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/xen/hypervisor.h b/include/asm-x86/xen/hypervisor.h
index 8e15dd2..06c3504 100644
--- a/include/asm-x86/xen/hypervisor.h
+++ b/include/asm-x86/xen/hypervisor.h
@@ -30,8 +30,8 @@
  * IN THE SOFTWARE.
  */
 
-#ifndef __HYPERVISOR_H__
-#define __HYPERVISOR_H__
+#ifndef ASM_X86__XEN__HYPERVISOR_H
+#define ASM_X86__XEN__HYPERVISOR_H
 
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -70,4 +70,4 @@
 
 #define is_running_on_xen()	(xen_start_info ? 1 : 0)
 
-#endif /* __HYPERVISOR_H__ */
+#endif /* ASM_X86__XEN__HYPERVISOR_H */