fix: adjust some code structure to satisfy linter

internal/downloader/downloader.go

@@ -40,7 +40,10 @@ func (c *Context) Download() error {
 		}
 		return err
 	}
-	defer resp.Close()
+	if err = resp.Close(); err != nil {
+		return err
+	}
+
 	if resp.StatusCode == http.StatusNotFound {
 		return ErrInvalidURL
 	}
@@ -50,19 +53,19 @@ func (c *Context) Download() error {
 	if resp.StatusCode != http.StatusOK {
 		return errors.New(resp.RawResponse.Status)
 	}
-	resp.Close()
 
 	resp, err = req.Get(c.Link, nil)
 	if err != nil {
 		return err
 	}
+	defer resp.Close()
 
 	var filesize int64
 	if resp.RawResponse.ContentLength > -1 {
 		filesize = resp.RawResponse.ContentLength
 	}
 
-	destFile, err := os.OpenFile(c.Filename, os.O_CREATE|os.O_WRONLY, 0644)
+	destFile, err := os.OpenFile(c.Filename, os.O_CREATE|os.O_WRONLY, 0600)
 	if err != nil {
 		return err
 	}