ALSA: xen-front: remove redundant error check on ret

The error for a -ve value in ret is redundant as all previous
assignments to ret have an associated -ve check and hence it
is impossible for ret to be less that zero at the point of the
check.  Remove this redundant error check.

Detected by CoveritScan, CID#1469407 ("Logically Dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/xen/xen_snd_front_evtchnl.c

@@ -351,8 +351,6 @@ int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
 			}
 		}
 	}
-	if (ret < 0)
-		goto fail;
 
 	front_info->num_evt_pairs = num_streams;
 	return 0;