uwb: hwa-rc: fix memory leak at probe

hwarc_probe() allocates memory for hwarc, but does not free it
if uwb_rc_add() or hwarc_get_version() fail.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/uwb/hwa-rc.c

@@ -873,6 +873,7 @@ static int hwarc_probe(struct usb_interface *iface,
 error_rc_add:
 	usb_put_intf(iface);
 	usb_put_dev(hwarc->usb_dev);
+	kfree(hwarc);
 error_alloc:
 	uwb_rc_put(uwb_rc);
 error_rc_alloc: