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 <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

drivers/s390/cio/chsc_sch.c

···
 	debug_set_level(chsc_debug_log_id, 2);
 	return 0;
 out:
-	if (chsc_debug_msg_id)
-		debug_unregister(chsc_debug_msg_id);
+	debug_unregister(chsc_debug_msg_id);
 	return -ENOMEM;
 }
 

drivers/s390/cio/cio.c

···
 	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;
 }
 

drivers/s390/cio/qdio_debug.c

···
 {
 	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);
 }

drivers/s390/crypto/zcrypt_api.c

···
 void zcrypt_debug_exit(void)
 {
 	debugfs_remove(debugfs_root);
-	if (zcrypt_dbf_common)
-		debug_unregister(zcrypt_dbf_common);
-	if (zcrypt_dbf_devices)
-		debug_unregister(zcrypt_dbf_devices);
+	debug_unregister(zcrypt_dbf_common);
+	debug_unregister(zcrypt_dbf_devices);
 }
 
 /**