usb: mtu3: unmap request DMA on queue failure

usb: mtu3: unmap request DMA on queue failure

mtu3_gadget_queue() maps the request before checking whether
the QMU GPD ring can accept another transfer. the request is
returned with -EAGAIN before it is linked on the endpoint
request list if mtu3_prepare_transfer() fails.

Normal completion and dequeue paths unmap requests from
mtu3_req_complete(), but this error path never reaches that
helper, so the DMA mapping is left active. Unmap the request
before returning from the failed queue path.

Fixes: df2069acb005 ("usb: Add MediaTek USB3 DRD driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Link: https://patch.msgid.link/20260623093325.2105323-1-haoxiang_li2024@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>