[nrf fromlist] drivers: wifi: Fix memory leak in regulatory processing

During Wi-Fi connection UMAC sends an unsolicited regulatory change
event but the driver code always assumes that this event is solicited
hence doesn't free the memory for the event.

Fix this by dropping the unsolicited event as it's not supported yet.

Fixes #79733.

Upstream PR: zephyrproject-rtos/zephyr#79891

Signed-off-by: Chaitanya Tata <[email protected]>

Author: krish2718

drivers/wifi/nrfwifi/src/fmac_main.c

@@ -474,6 +474,12 @@ void reg_change_callbk_fn(void *vif_ctx,
 		return;
 	}
 
+	if (!fmac_dev_ctx->waiting_for_reg_event) {
+		LOG_DBG("%s: Unsolicited regulatory change event", __func__);
+		/* TODO: Handle unsolicited regulatory change event */
+		return;
+	}
+
 	fmac_dev_ctx->reg_change = k_malloc(sizeof(struct nrf_wifi_event_regulatory_change));
 	if (!fmac_dev_ctx->reg_change) {
 		LOG_ERR("%s: Failed to allocate memory for reg_change", __func__);