ALSA: usb-audio: spelling correction

Correct spelling of snd_usb_endpoint_implict_feedback_sink in all
occurances.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 652724c..754cb5b 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -1271,7 +1271,7 @@
 			}
 		}
 		if (period_elapsed &&
-		    !snd_usb_endpoint_implict_feedback_sink(subs->data_endpoint)) /* finish at the period boundary */
+		    !snd_usb_endpoint_implicit_feedback_sink(subs->data_endpoint)) /* finish at the period boundary */
 			break;
 	}
 	bytes = frames * stride;