greybus: gb-audio: Reset sample count when CPort deactivated

The sample count placed in Greybus I2S audio messages should be
reset every time a new audio stream is set up.  However, the
current code does not do the reset so make it so it does.

Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/audio-pcm.c

@@ -57,6 +57,7 @@ static void gb_pcm_work(struct work_struct *work)
 				pr_err("deactivate_cport failed: %d\n", ret);
 
 			snd_dev->cport_active = false;
+			snd_dev->send_data_sample_count = 0;
 		}
 
 		return;