fix: possible goroutine leak in exec

If timeout happens and ShouldWait is false (default) cmd.Wait()
goroutine will stack forever on sending to done channel.
The will be no receiver from done.
Making the channel buffered lets the goroutine exit.

Signed-off-by: Anton Tiurin <[email protected]>

exec/exec.go

@@ -111,7 +111,7 @@ func RunCommandExt(cmd *exec.Cmd, opts CmdOpts) (string, error) {
 		return "", err
 	}
 
-	done := make(chan error)
+	done := make(chan error, 1)
 	go func() { done <- cmd.Wait() }()
 
 	// Start a timer