usb: gadget: amd5536udc: unconditionally use GFP_ATOMIC in udc_queue()

As far as prep_dma() is called with spinlock held,
we have to pass GFP_ATOMIC regardless of gfp argument.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/amd5536udc.c b/drivers/usb/gadget/amd5536udc.c
index f52dcfe..a9a4346 100644
--- a/drivers/usb/gadget/amd5536udc.c
+++ b/drivers/usb/gadget/amd5536udc.c
@@ -1122,7 +1122,7 @@
 			goto finished;
 		}
 		if (ep->dma) {
-			retval = prep_dma(ep, req, gfp);
+			retval = prep_dma(ep, req, GFP_ATOMIC);
 			if (retval != 0)
 				goto finished;
 			/* write desc pointer to enable DMA */
@@ -1190,7 +1190,7 @@
 		 * for PPB modes, because of chain creation reasons
 		 */
 		if (ep->in) {
-			retval = prep_dma(ep, req, gfp);
+			retval = prep_dma(ep, req, GFP_ATOMIC);
 			if (retval != 0)
 				goto finished;
 		}