When softap is stopping, there are two threads
accessing the "conc_connection_list".
hostapd thread (__wlan_hdd_cfg80211_stop_ap) read
and modify it by cds_decr_session_set_pcl.
cds_mc_thread thread (cds_get_valid_chan_weights)
read and modify it by cds_store_and_del_conn_info
and cds_restore_deleted_conn_info.
They are not protected,which causes two same
station connection info saved to the
"conc_connection_list".
This fix is to acquire lock before read/modify
the list.
Change-Id: I5f1becef711363f659044c46e69fab1cd6d07d81
CRs-Fixed: 2038000
f45a0df7e2