tests: net: context: Fix tests when using locking

There was a false timeout error because we did not check the
return value correctly. This issue is seen now because code
flow in core IP stack is happening in different order than
before.

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

Author: jukkar

tests/net/context/src/main.c

@@ -766,7 +766,7 @@ void timeout_thread(struct net_context *ctx, void *param2, void *param3)
 		return;
 	}
 
-	if (recv_cb_timeout_called) {
+	if (!recv_cb_timeout_called) {
 		DBG("Data received on time, recv test failed\n");
 		cb_failure = true;
 		return;