remove usage from tests

container.go

@@ -94,6 +94,7 @@ func ParseRun(args []string, capabilities *Capabilities) (*Config, *HostConfig,
 	cmd := Subcmd("run", "[OPTIONS] IMAGE [COMMAND] [ARG...]", "Run a command in a new container")
 	if len(args) > 0 && args[0] != "--help" {
 		cmd.SetOutput(ioutil.Discard)
+		cmd.Usage = nil
 	}
 
 	flHostname := cmd.String("h", "", "Container host name")