uas: Use GFP_NOIO rather then GFP_ATOMIC where possible

We can sleep in our own workqueue (which is the whole reason for having
it), and scsi error handlers are also always called from a context which
may sleep.

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