qcacmn: Fix NULL pointer dereference in extract_hal_reg_cap_tlv

In extract_hal_reg_cap_tlv(), field hal_reg_capabilities of
param_buf may be NULL, when access field wireless_modes of
hal_reg_capabilities, it will result in a NULL pointer access.

Fix is to add NULL pointer check for field hal_reg_capabilities
of param_buf.

Change-Id: Ie2a50ce1f06f9623cc771d4d580cb5f9f25cc5d4
CRs-Fixed: 2387212

wmi/src/wmi_unified_tlv.c

@@ -7976,7 +7976,7 @@ static QDF_STATUS extract_hal_reg_cap_tlv(wmi_unified_t wmi_handle,
 	WMI_SERVICE_READY_EVENTID_param_tlvs *param_buf;
 
 	param_buf = (WMI_SERVICE_READY_EVENTID_param_tlvs *) evt_buf;
-	if (!param_buf) {
+	if (!param_buf || !param_buf->hal_reg_capabilities) {
 		WMI_LOGE("%s: Invalid arguments", __func__);
 		return QDF_STATUS_E_FAILURE;
 	}