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/uaccess.h b/arch/x86/include/asm/uaccess.h
index 48ebc0a..35c5492 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -1,5 +1,5 @@
-#ifndef ASM_X86__UACCESS_H
-#define ASM_X86__UACCESS_H
+#ifndef _ASM_X86_UACCESS_H
+#define _ASM_X86_UACCESS_H
 /*
  * User space memory access functions
  */
@@ -450,5 +450,5 @@
 # include "uaccess_64.h"
 #endif
 
-#endif /* ASM_X86__UACCESS_H */
+#endif /* _ASM_X86_UACCESS_H */