If an active transfer is dequeued, then the endpoint is freed to start a
new transfer. Make sure to clear the endpoint's transfer wait flag for
this case.

Fixes: e0d19563 ("usb: dwc3: gadget: Wait for transfer completion")
Cc: stable@vger.kernel.org
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/b81cd5b5281cfbfdadb002c4bcf5c9be7c017cfd.1609828485.git.Thinh.Nguyen@synopsys.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>