The error handling in rtl8152_probe() is missing a call to release
firmware. Add it in to match what's in the cleanup code in
rtl8152_disconnect().

Fixes: 9370f2d0 ("r8152: support request_firmware for RTL8153")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>