samples: net: echo_service: Fix documentation

Clarify the documentation in the README.rst file. Also remove the
obsolete comment from main.c as it is no longer correct.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

samples/net/sockets/echo_service/README.rst

@@ -7,8 +7,8 @@
 Overview
 ********
 
-The sockets/echo_service sample application for Zephyr implements a TCP echo
-server supporting both IPv4 and IPv6 and using a BSD Sockets compatible API.
+The sockets/echo_service sample application for Zephyr implements a TCP and UDP
+echo server supporting both IPv4 and IPv6 and using a BSD Sockets compatible API.
 
 The purpose of this sample is to show how to use socket service API.
 The socket service is a concept where many blocking sockets can be listened by

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

@@ -38,11 +38,6 @@ static void tcp_service_handler(struct net_socket_service_event *pev)
 {
 	static char buf[1500];
 
-	/* Note that in this application we receive / send data from
-	 * system work queue. In proper application the socket reading and data
-	 * sending should be done so that the system work queue is not blocked.
-	 * It is possible to create a socket service that uses own work queue.
-	 */
 	receive_data(false, pev, buf, sizeof(buf));
 }