fotg210-udc: Complete OUT requests on short packets

[ Upstream commit 75bb93be0027123b5db6cbcce89eb62f0f6b3c5b ]

A short packet indicates the end of a transfer and marks the request as
complete.

Fixes: b84a8dee ("usb: gadget: add Faraday fotg210_udc driver")
Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de>
Link: https://lore.kernel.org/r/20210324141115.9384-8-fabian@ritter-vogt.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>