rtl8xxxu: prevent leaking urb

BugLink: https://bugs.launchpad.net/bugs/1859865

commit a2cdd074 upstream.

In rtl8xxxu_submit_int_urb if usb_submit_urb fails the allocated urb
should be released.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c

@@ -5135,6 +5135,7 @@ static int rtl8xxxu_submit_int_urb(struct ieee80211_hw *hw)
 	ret = usb_submit_urb(urb, GFP_KERNEL);
 	if (ret) {
 		usb_unanchor_urb(urb);
+		usb_free_urb(urb);
 		goto error;
 	}