samples: net: sockets: coap_download: Cancel requests before closing

Call coap_client_cancel_requests() before closing the client socket so
that all activities on that socket are ceased before close. This
prevents POLLNVAL error from being thrown by the coap_client thread and
error being printed in the sample output.

Signed-off-by: Robert Lubos <[email protected]>

Author: rlubos

samples/net/sockets/coap_download/src/main.c

@@ -82,6 +82,8 @@ static void do_coap_download(struct sockaddr *sa)
 	/* Wait for CoAP request to complete */
 	k_sem_take(&coap_done_sem, K_FOREVER);
 
+	coap_client_cancel_requests(&client);
+
 	zsock_close(sockfd);
 }