atp_open(), atp_recover() and atp_resume() are never called in atomic
context. They call usb_submit_urb() with GFP_ATOMIC, which is not
necessary. GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>