Fix silly little syntax mistake

Signed-off-by: Andrew "Tianon" Page <admwiggin@gmail.com>
Upstream-commit: 6292354dc359a6d8f47b3199284147d557d2c697
Component: engine

components/engine/api/client/utils.go

@@ -260,7 +260,7 @@ func (cli *DockerCli) monitorTtySize(id string, isExec bool) error {
 	sigchan := make(chan os.Signal, 1)
 	gosignal.Notify(sigchan, signal.SIGWINCH)
 	go func() {
-		for _ := range sigchan {
+		for _ = range sigchan {
 			cli.resizeTty(id, isExec)
 		}
 	}()