UPSTREAM: usb: gadget: f_fs: Fix unbalanced spinlock in __ffs_ep0_queue_wait

__ffs_ep0_queue_wait executes holding the spinlock of &ffs->ev.waitq.lock
and unlocks it after the assignments to usb_request are done.
However in the code if the request is already NULL we bail out returning
-EINVAL but never unlocked the spinlock.

Fix this by adding spin_unlock_irq &ffs->ev.waitq.lock before returning.

Fixes: 6a19da11 ("usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait")
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Link: https://lore.kernel.org/r/20230124091149.18647-1-quic_ugoswami@quicinc.com


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

BUG: 266631160
Bug: 269722315
(cherry picked from commit 921deb9d usb-linus)
Change-Id: I7cd4445a6e1eee431fd1a1848b114181f4eea45c
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Signed-off-by: Yinchu Chen <chenyc5@motorola.com>