qcacld-3.0: Check validity of the adapter before access

Fix errors reported by static source analysis tool by
validating the adapter to make sure it is not NULL
before access.

Change-Id: I312da3ebf6913e5b8999a9ad9dc4eaa6ae08234b
CRs-Fixed: 1027065

core/hdd/src/wlan_hdd_main.c

@@ -5048,7 +5048,7 @@ static void hdd_set_thermal_level_cb(void *context, u_int8_t level)
 /**
  * hdd_get_safe_channel_from_pcl_and_acs_range() - Get safe channel for SAP
  * restart
- * @adapter: AP adapter
+ * @adapter: AP adapter, which should be checked for NULL
  *
  * Get a safe channel to restart SAP. PCL already takes into account the
  * unsafe channels. So, the PCL is validated with the ACS range to provide
@@ -5352,6 +5352,11 @@ static void hdd_ch_avoid_cb(void *hdd_context, void *indi_param)
 	while (NULL != adapter_node && QDF_STATUS_SUCCESS == status) {
 		adapter_temp = adapter_node->pAdapter;
 
+		if (!adapter_temp) {
+			hdd_err("adapter is NULL, moving to next one");
+			goto next_adapater;
+		}
+
 		if (!((adapter_temp->device_mode == QDF_SAP_MODE) &&
 		   (adapter_temp->sessionCtx.ap.sapConfig.acs_cfg.acs_mode))) {
 			hdd_info("skip device mode:%d acs:%d",