ALSA: line6: fix check on snd_card_register

The fix checks if snd_card_register() fails, and if so logs the error
via dev_err() consistent with other patches.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/line6/pod.c

@@ -320,7 +320,8 @@ static void pod_startup4(struct work_struct *work)
 	line6_read_serial_number(&pod->line6, &pod->serial_number);
 
 	/* ALSA audio interface: */
-	snd_card_register(line6->card);
+	if (snd_card_register(line6->card))
+		dev_err(line6->ifcdev, "Failed to register POD card.\n");
 }
 
 /* POD special files: */