mt7601u: process tx URBs with status EPROTO properly

Similar to commit 0e40dbd5 ("mt7601u: process URBs in status EPROTO
properly"), do not process tx URBs if marked with status set to EPROTO.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/72392e8341aa8591c0b9962661a6ca26b1198f32.1610919534.git.lorenzo@kernel.org