net/wan/fsl_ucc_hdlc: Avoid double free in ucc_hdlc_probe()

This patch fixes potential double frees if register_hdlc_device() fails.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Peng Hao <peng.hao2@zte.com.cn>
CC: Zhao Qiang <qiang.zhao@nxp.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>