octeontx2-af: cn10k: mcs: Fix error return code in mcs_register_interrupts()

commit fae2871cca6d7a29c49df95f3a53d073843ab19e from
git@git.assembla.com:cavium/WindRiver.linux.git

If alloc_mem() fails in mcs_register_interrupts(), it should return error
code.

Fixes: 4674408abfe4 ("octeontx2-af: mcs: Add SA interrupt handling support")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change-Id: Iacaec94e6e694622eed62cb9fb99041551858410
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/90161


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>