s390: Delete unnecessary checks before the function call "debug_unregister"

The debug_unregister() function performs also input parameter validation.
Thus the test around the calls is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index e0d0295..2d18205 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -76,12 +76,9 @@
 	return 0;
 
 out_unregister:
-	if (cio_debug_msg_id)
-		debug_unregister(cio_debug_msg_id);
-	if (cio_debug_trace_id)
-		debug_unregister(cio_debug_trace_id);
-	if (cio_debug_crw_id)
-		debug_unregister(cio_debug_crw_id);
+	debug_unregister(cio_debug_msg_id);
+	debug_unregister(cio_debug_trace_id);
+	debug_unregister(cio_debug_crw_id);
 	return -1;
 }