sound: oss: uart401: remove unneeded NULL check

"devc" can't be NULL here so there is no need to check.  Also I removed
the "devc = NULL" assignment because devc is stored on stack so it's
a no-op.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/oss/uart401.c

@@ -412,13 +412,10 @@ void unload_uart401(struct address_info *hw_config)
 
 	if (!devc->share_irq)
 		free_irq(devc->irq, devc);
-	if (devc)
-	{
-		kfree(midi_devs[devc->my_dev]->converter);
-		kfree(midi_devs[devc->my_dev]);
-		kfree(devc);
-		devc = NULL;
-	}
+	kfree(midi_devs[devc->my_dev]->converter);
+	kfree(midi_devs[devc->my_dev]);
+	kfree(devc);
+
 	/* This kills midi_devs[x] */
 	sound_unload_mididev(hw_config->slots[4]);
 }