s390: use canonical include guard style

Signed-off-by: Daniel van Gerpen <daniel@vangerpen.de>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/chp.h b/drivers/s390/cio/chp.h
index af02322..bb5a682 100644
--- a/drivers/s390/cio/chp.h
+++ b/drivers/s390/cio/chp.h
@@ -4,7 +4,7 @@
  */
 
 #ifndef S390_CHP_H
-#define S390_CHP_H S390_CHP_H
+#define S390_CHP_H
 
 #include <linux/types.h>
 #include <linux/device.h>