qcacmn: Null pointer access in green ap egap status event

While extracting green ap egap status info there is no
sanity check for egap info event and chainmask event which may
lead to NULL pointer access.

To prevent this NULL pointer access add a sanity check for
egap info event and chainmask event.

Change-Id: Ib9cc273f12bb159bce309065279230e96925be7f
CRs-Fixed: 2331873

wmi/src/wmi_unified_tlv.c

@@ -10541,6 +10541,11 @@ static QDF_STATUS extract_green_ap_egap_status_info_tlv(
 	chainmask_event = (wmi_ap_ps_egap_info_chainmask_list *)
 				param_buf->chainmask_list;
 
+	if (!egap_info_event || !chainmask_event) {
+		WMI_LOGE("Invalid EGAP Info event or chainmask event");
+		return QDF_STATUS_E_INVAL;
+	}
+
 	egap_status_info_params->status = egap_info_event->status;
 	egap_status_info_params->mac_id = chainmask_event->mac_id;
 	egap_status_info_params->tx_chainmask = chainmask_event->tx_chainmask;