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/ia32_unistd.h b/arch/x86/include/asm/ia32_unistd.h
index dbd887d..976f6ec 100644
--- a/arch/x86/include/asm/ia32_unistd.h
+++ b/arch/x86/include/asm/ia32_unistd.h
@@ -1,5 +1,5 @@
-#ifndef ASM_X86__IA32_UNISTD_H
-#define ASM_X86__IA32_UNISTD_H
+#ifndef _ASM_X86_IA32_UNISTD_H
+#define _ASM_X86_IA32_UNISTD_H
 
 /*
  * This file contains the system call numbers of the ia32 port,
@@ -15,4 +15,4 @@
 #define __NR_ia32_sigreturn	119
 #define __NR_ia32_rt_sigreturn	173
 
-#endif /* ASM_X86__IA32_UNISTD_H */
+#endif /* _ASM_X86_IA32_UNISTD_H */