usb: gadget: fsl: Initialize udc before using it

fsl_ep_queue() is only called by usb_ep_queue() (as ep->ops->queue()).
So _ep isn't NULL.

As ep->ops->queue = fsl_ep_queue, the ep was initialized by
struct_ep_setup() and so ep->udc isn't NULL either.

Drop the check for _ep being NULL and assign udc earlier to prevent
following an uninitialized pointer in the two dev_vdbg()s in lines 878
and 882. This fixes a compiler warning when using clang and
CONFIG_USB_GADGET_VERBOSE=y.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404050227.TTvcCPBu-lkp@intel.com/
Fixes: 6025f20 ("usb: gadget: fsl-udc: Replace custom log wrappers by dev_{err,warn,dbg,vdbg}")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20240405055812.694123-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Uwe Kleine-König

drivers/usb/gadget/udc/fsl_udc_core.c

@@ -868,7 +868,7 @@ fsl_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
 {
 	struct fsl_ep *ep = container_of(_ep, struct fsl_ep, ep);
 	struct fsl_req *req = container_of(_req, struct fsl_req, req);
-	struct fsl_udc *udc;
+	struct fsl_udc *udc = ep->udc;
 	unsigned long flags;
 	int ret;
 
@@ -878,7 +878,7 @@ fsl_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
 		dev_vdbg(&udc->gadget.dev, "%s, bad params\n", __func__);
 		return -EINVAL;
 	}
-	if (unlikely(!_ep || !ep->ep.desc)) {
+	if (unlikely(!ep->ep.desc)) {
 		dev_vdbg(&udc->gadget.dev, "%s, bad ep\n", __func__);
 		return -EINVAL;
 	}
@@ -887,7 +887,6 @@ fsl_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
 			return -EMSGSIZE;
 	}
 
-	udc = ep->udc;
 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN)
 		return -ESHUTDOWN;