octeontx2-pf: mcs: fix missing unlock in some error paths

commit 2807e535781495f2c2a05214750a57a56ba09a37 from
git@git.assembla.com:cavium/WindRiver.linux.git

Add the missing unlock in some error paths.

Fixes: f6aeb48748b29 ("octeontx2-pf: mcs: Introduce MACSEC hardware offloading")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change-Id: I8d57898eaf8b80ba9290dae18ef909b4b048bbd4
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/90160


Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Beniamin Sandu <beniamin.sandu@windriver.com>