media: usb: em28xx: Replace GFP_ATOMIC with GFP_KERNEL in em28xx_init_usb_xfer()

em28xx_init_usb_xfer() is never called in atomic context.
It calls 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: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/usb/em28xx/em28xx-core.c

@@ -1053,7 +1053,7 @@ int em28xx_init_usb_xfer(struct em28xx *dev, enum em28xx_mode mode,
 
 	/* submit urbs and enables IRQ */
 	for (i = 0; i < usb_bufs->num_bufs; i++) {
-		rc = usb_submit_urb(usb_bufs->urb[i], GFP_ATOMIC);
+		rc = usb_submit_urb(usb_bufs->urb[i], GFP_KERNEL);
 		if (rc) {
 			dev_err(&dev->intf->dev,
 				"submit of urb %i failed (error=%i)\n", i, rc);