staging: emxx_udc: Replace GFP_KERNEL with GFP_ATOMIC

To avoid deadlock, do not call blocking functions with spinlocks held.

Replace GFP_KERNEL with GFP_ATOMIC, as the latter will fail if the pile
doesn't have enough free pages but will not sleep and hence deadlock can
be avoided.

Found by Coccinelle.
Signed-off-by: Tapasweni Pathak <tapaswenipathak@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/emxx_udc/emxx_udc.c

@@ -2794,7 +2794,7 @@ static int nbu2ss_ep_queue(
 		if (ep->virt_buf == NULL)
 			ep->virt_buf = (u8 *)dma_alloc_coherent(
 				NULL, PAGE_SIZE,
-				&ep->phys_buf, GFP_KERNEL | GFP_DMA);
+				&ep->phys_buf, GFP_ATOMIC | GFP_DMA);
 		if (ep->epnum > 0)  {
 			if (ep->direct == USB_DIR_IN)
 				memcpy(ep->virt_buf, req->req.buf,