ALSA: usb-audio: Fix some typos

Fix the following typos in comments and in the code:
 - KHz -> kHz
 - procssed -> processed

Signed-off-by: Alexander Tsoy <alexander@tsoy.me>
Link: https://lore.kernel.org/r/20200629032607.255419-1-alexander@tsoy.me
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 84c0ae4..2b47f7f 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -1694,8 +1694,8 @@ static void retire_playback_urb(struct snd_usb_substream *subs,
 	int processed = urb->transfer_buffer_length / ep->stride;
 	int est_delay;
 
-	/* ignore the delay accounting when procssed=0 is given, i.e.
-	 * silent payloads are procssed before handling the actual data
+	/* ignore the delay accounting when processed=0 is given, i.e.
+	 * silent payloads are processed before handling the actual data
 	 */
 	if (!processed)
 		return;