UPSTREAM: usb: gadget: uvc: only schedule stream in streaming state

This patch ensures that the video pump thread will only be scheduled if
the uvc is really in streaming state. This way the worker will not have
to run on an empty queue.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20211017215017.18392-5-m.grzeschik@pengutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry picked from commit 5fc49d8b)
Bug: 242344221
Change-Id: I9b38b336d69e1840de6c557ad52d5f0c5e2afc96
Signed-off-by: Avichal Rakesh <arakesh@google.com>