[S390] cio: css_sch_device_register() can be made static.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index dfca0ef..eb08d63 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -109,7 +109,7 @@
 	}
 }
 
-int css_sch_device_register(struct subchannel *sch)
+static int css_sch_device_register(struct subchannel *sch)
 {
 	int ret;