net: tests: Fix mqtt_subscriber

Remove redundant mqtt_init() call, and fix sense of test for
mqtt_init().

Signed-off-by: Gil Pitney <gil.pitney@linaro.org>

tests/net/lib/mqtt_subscriber/src/test_mqtt_subscribe.c

@@ -247,31 +247,19 @@ static int init_network(void)
 
 	/* connect, disconnect and malformed may be set to NULL */
 	client_ctx.mqtt_ctx.connect = connect_cb;
-
 	client_ctx.mqtt_ctx.disconnect = disconnect_cb;
-
 	client_ctx.mqtt_ctx.malformed = malformed_cb;
-
 	client_ctx.mqtt_ctx.subscribe = subscriber_cb;
-
 	client_ctx.mqtt_ctx.unsubscribe = unsubscribe_cb;
 
 	client_ctx.mqtt_ctx.net_init_timeout = APP_NET_INIT_TIMEOUT;
-
 	client_ctx.mqtt_ctx.net_timeout = APP_TX_RX_TIMEOUT;
-
 	client_ctx.mqtt_ctx.peer_addr_str = SERVER_ADDR;
-
 	client_ctx.mqtt_ctx.peer_port = SERVER_PORT;
 
 	/* Publisher apps TX the MQTT PUBLISH msg */
 	client_ctx.mqtt_ctx.publish_rx = publish_rx_cb;
 
-	rc = mqtt_init(&client_ctx.mqtt_ctx, MQTT_APP_SUBSCRIBER);
-	if (rc != 0) {
-		goto exit_app;
-	}
-
 	/* The connect message will be sent to the MQTT server (broker).
 	 * If clean_session here is 0, the mqtt_ctx clean_session variable
 	 * will be set to 0 also. Please don't do that, set always to 1.
@@ -292,7 +280,7 @@ static int init_network(void)
 	}
 
 	rc = mqtt_connect(&client_ctx.mqtt_ctx);
-	if (!rc) {
+	if (rc != 0) {
 		goto exit_app;
 	}