usb: dwc3: ep0: remove redundant assignment

In

	dwc3_request	*r = NULL;
	r = A;

the first assignment has no effect. Remove it.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/ep0.c

@@ -814,7 +814,7 @@ out:
 static void dwc3_ep0_complete_data(struct dwc3 *dwc,
 		const struct dwc3_event_depevt *event)
 {
-	struct dwc3_request	*r = NULL;
+	struct dwc3_request	*r;
 	struct usb_request	*ur;
 	struct dwc3_trb		*trb;
 	struct dwc3_ep		*ep0;