server: revert commit 7e6556b3ca

With the removal of old tpiu code, commit 7e6556b3ca ("server:
permit the add_service function to return the created service")
http://openocd.zylin.com/5717/ can be reverted.

Fix also the new calls to add_service().

Change-Id: Ib7f2dfc6a9e829239e20313e0f121911085fdc00
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/6031
Tested-by: jenkins
Reviewed-by: Adrian M Negreanu <adrian.negreanu@nxp.com>

src/server/server.c

@@ -210,8 +210,7 @@ int add_service(char *name,
 	new_connection_handler_t new_connection_handler,
 	input_handler_t input_handler,
 	connection_closed_handler_t connection_closed_handler,
-	void *priv,
-	struct service **new_service)
+	void *priv)
 {
 	struct service *c, **p;
 	struct hostent *hp;
@@ -347,10 +346,6 @@ int add_service(char *name,
 		;
 	*p = c;
 
-	/* if new_service is not NULL, return the created service into it */
-	if (new_service)
-		*new_service = c;
-
 	return ERROR_OK;
 }