Allow an onrestart command to stop the current service

For example,

service recovery /sbin/recovery
	onrestart start loadkeys
	onrestart class_start con
	onrestart stop recovery

Previously, if you had a service like the above, the "onrestart stop
recovery" clause would not have any effect, because the restart flag
would be re-set after the stop command had executed.

This is similar to a service with the "oneshot" keyword, with the critical
difference being that it executes the other onrestart commands when the
service dies.

init/init.c

@@ -389,12 +389,13 @@ static int wait_for_one_process(int block)
         }
     }
 
+    svc->flags |= SVC_RESTARTING;
+
     /* Execute all onrestart commands for this service. */
     list_for_each(node, &svc->onrestart.commands) {
         cmd = node_to_item(node, struct command, clist);
         cmd->func(cmd->nargs, cmd->args);
     }
-    svc->flags |= SVC_RESTARTING;
     notify_service_state(svc->name, "restarting");
     return 0;
 }