st_nci_hci_connectivity_event_received: null check the allocation

[ Upstream commit 3008e06f ]

devm_kzalloc may fail and return NULL. So the null check is needed.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>