uas: no gfp argument to uas_submit_urbs()

This function must be called with a spinlock held.
Memory can be allocated only with GFP_ATOMIC. Passing
a gfp_t argument is a waste.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>