usb: gadget: f_tcm: Stop proceeding further on -ESHUTDOWN

If the error code is -ESHUTDOWN, stop processing the request/command
further and prepare for teardown. -ESHUTDOWN is for device reset or
disconnection.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/b14410cce6bc7b8a0b43da23a8e0cf1ed1fa8ab6.1733876548.git.Thinh.Nguyen@synopsys.com


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