wlan: check if tdls exists when tdls peer timer expires.

when wlan_hdd_tdls_initiator_wait_cb gets called, the tdls peer
might not exists as there is a chance that the peer may get deleted
as part of disconnection.

So check if tdls exists before accessing the peer in
wlan_hdd_tdls_initiator_wait_cb.

Change-Id: I90a7a765997bf3641bf2c8de2f3c9e5068e89122
CRs-Fixed: 906303
diff --git a/CORE/HDD/inc/wlan_hdd_main.h b/CORE/HDD/inc/wlan_hdd_main.h
index b928904..823e11c 100644
--- a/CORE/HDD/inc/wlan_hdd_main.h
+++ b/CORE/HDD/inc/wlan_hdd_main.h
@@ -1569,6 +1569,8 @@
 void hdd_dump_concurrency_info(hdd_context_t *pHddCtx);
 hdd_adapter_t * hdd_get_adapter_by_name( hdd_context_t *pHddCtx, tANI_U8 *name );
 hdd_adapter_t * hdd_get_adapter_by_macaddr( hdd_context_t *pHddCtx, tSirMacAddr macAddr );
+hdd_adapter_t *hdd_get_adapter_by_sme_session_id( hdd_context_t *pHddCtx,
+                                        tANI_U32 sme_session_id );
 hdd_adapter_t * hdd_get_mon_adapter( hdd_context_t *pHddCtx );
 VOS_STATUS hdd_init_station_mode( hdd_adapter_t *pAdapter );
 hdd_adapter_t * hdd_get_adapter( hdd_context_t *pHddCtx, device_mode_t mode );