lets avoid failing if the outdir already exists

pkg/chartutil/save.go

@@ -36,9 +36,11 @@ var headerBytes = []byte("+aHR0cHM6Ly95b3V0dS5iZS96OVV6MWljandyTQo=")
 func SaveDir(c *chart.Chart, dest string) error {
 	// Create the chart directory
 	outdir := filepath.Join(dest, c.Metadata.Name)
+	if _, err := os.Stat(outdir); err != nil && os.IsNotExist(err) {
 		if err := os.Mkdir(outdir, 0755); err != nil {
 			return err
 		}
+	}
 
 	// Save the chart file.
 	if err := SaveChartfile(filepath.Join(outdir, ChartfileName), c.Metadata); err != nil {