HID: sony: remove duplicate NULL check before calling usb_free_urb()

usb_free_urb() does the NULL check itself, so there is no need to duplicate
it prior to calling.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: e1cd4004 ("HID: sony: Fix a potential memory leak in sony_probe()")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-sony.c

@@ -2155,7 +2155,6 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	return ret;
 
 err:
-	if (sc->ghl_urb)
 	usb_free_urb(sc->ghl_urb);
 
 	hid_hw_stop(hdev);