qcacld-3.0: Check acs_cfg is Null

When AP mode is not initialized done, trigger AP scan manual maybe crash,
since acs_cfg maybe null.

Change-Id: I1b5f5eb301a10661a75557dcd9d4fc1fa1b9819b
CRs-Fixed: 3478487

core/sap/src/sap_api_link_cntl.c

@@ -1669,6 +1669,12 @@ void wlansap_process_chan_info_event(struct sap_context *sap_ctx,
 
 	if (sap_ctx->optimize_acs_chan_selected)
 		return;
+
+	if (!sap_ctx->acs_cfg) {
+		sap_debug("acs_cfg is null");
+		return;
+	}
+
 	/* If chan_info_freq is not preferred band's freq
 	 * do not select it as ACS result.
 	 */