In P2P connect process, GO and GC send deauth/disassoc at the
end of WPS. GO send disassoc and free station info. GO receive
deauth from GC, and send cmd WLAN_SER_CMD_GET_DISCONNECT_STATS
to get disconnect stats.
If GO send deauth and free peer info before receive deauth
from GC. Wlan_objmgr_get_peer return null, and peer is null.
Cmd of WLAN_SER_CMD_GET_DISCONNECT_STATS will never be
released since get_peer_rssi_cb will never be called.
And cmd will timeout, which is not expected.
If we call get_peer_rssi_cb without check, cmd will release.
Also csr_get_peer_rssi_cb will check peer is null or not.
Change-Id: I10b496526e259711a4dd7a91b7388ac79bb54fef
CRs-Fixed: 3119513
6e475e2bff