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/i387.h b/arch/x86/include/asm/i387.h
index 9ba862a..48f0004 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -7,8 +7,8 @@
  * x86-64 work by Andi Kleen 2002
  */
 
-#ifndef ASM_X86__I387_H
-#define ASM_X86__I387_H
+#ifndef _ASM_X86_I387_H
+#define _ASM_X86_I387_H
 
 #include <linux/sched.h>
 #include <linux/kernel_stat.h>
@@ -397,4 +397,4 @@
 	}
 }
 
-#endif /* ASM_X86__I387_H */
+#endif /* _ASM_X86_I387_H */