uas: Fix reset handling for externally triggered reset

Handle usb-device resets not triggered from uas_eh_bus_reset_handler(), when
this happens, disable cmd queuing during the reset, and wait for existing
requests to finish in pre_reset.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>