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/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index f1f3baa..b6fc147 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -366,8 +366,6 @@
 {
 	qdio_clear_dbf_list();
 	debugfs_remove(debugfs_root);
-	if (qdio_dbf_setup)
-		debug_unregister(qdio_dbf_setup);
-	if (qdio_dbf_error)
-		debug_unregister(qdio_dbf_error);
+	debug_unregister(qdio_dbf_setup);
+	debug_unregister(qdio_dbf_error);
 }