UAPI: Alter the S390 asm include guards to be recognisable by the UAPI splitter

Alter some of the S390 asm include guards to fit a pattern that the UAPI
splitter recognises.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/arch/s390/include/asm/chpid.h b/arch/s390/include/asm/chpid.h
index fc71d8a..8e88e22 100644
--- a/arch/s390/include/asm/chpid.h
+++ b/arch/s390/include/asm/chpid.h
@@ -6,7 +6,7 @@
  */
 
 #ifndef _ASM_S390_CHPID_H
-#define _ASM_S390_CHPID_H _ASM_S390_CHPID_H
+#define _ASM_S390_CHPID_H
 
 #include <linux/string.h>
 #include <linux/types.h>