qcacmn: use spinlock before iterating

Before iterating in pending list, use spinlock to avoid possible
race condition.
Remove function wlan_serialization_get_active_list_next_node_using_psoc
as it not being used and is part of legacy flow which is suppose to be
removed eventually.

Change-Id: I9e7cbd9db8b5a1c45915bf5291cd5011c276d0e2
CRs-Fixed: 2573425
2 files changed