drivers: bluetooth: hci_nxp: fix nomem handling

When allocation fails in `hci_rx_cb`, we should return immediately
instead of continuing the execution of the function.

Also, we need to free the allocated buffer from the heap when sending
to the message queue fails to avoid memory leak.

Signed-off-by: Axel Le Bourhis <axel.lebourhis@nxp.com>

Author: axelnxp

drivers/bluetooth/hci/hci_nxp.c

@@ -368,19 +368,23 @@ K_THREAD_DEFINE(nxp_hci_rx_thread, CONFIG_BT_DRV_RX_STACK_SIZE, bt_rx_thread, NU
 static void hci_rx_cb(uint8_t packetType, uint8_t *data, uint16_t len)
 {
 	struct hci_data hci_rx_frame;
+	int ret;
 
 	hci_rx_frame.packetType = packetType;
 	hci_rx_frame.data = k_malloc(len);
 
 	if (!hci_rx_frame.data) {
 		LOG_ERR("Failed to allocate RX buffer");
+		return;
 	}
 
 	memcpy(hci_rx_frame.data, data, len);
 	hci_rx_frame.len = len;
 
-	if (k_msgq_put(&rx_msgq, &hci_rx_frame, K_NO_WAIT) < 0) {
-		LOG_ERR("Failed to push RX data to message queue");
+	ret = k_msgq_put(&rx_msgq, &hci_rx_frame, K_NO_WAIT);
+	if (ret < 0) {
+		LOG_ERR("Failed to push RX data to message queue: %d", ret);
+		k_free(hci_rx_frame.data);
 	}
 }