There are a couple failure paths where urb leaks.
Is spare code within ems_usb_start_xmit(),
usb_free_urb() should be used to deallocate urb instead of usb_unanchor_urb().
In ems_usb_start() there is no usb_free_urb() if usb_submit_urb() fails.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: NSebastian Haas <dev@sebastianhaas.info>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>