Accept some golint suggestions (#690)

* Fixed some linter issues

* Simplified isBetter method

* Accept some linter suggestions

* Fix typo

Co-authored-by: klesomik <klesomiks@gmail.com>
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

src/util/cancellation.go

@@ -54,12 +54,11 @@ func (c *cancellation) Cancel(err error) error {
 	defer c.mutex.Unlock()
 	if c.done {
 		return c.err
-	} else {
-		c.err = err
-		c.done = true
-		close(c.cancel)
-		return nil
 	}
+	c.err = err
+	c.done = true
+	close(c.cancel)
+	return nil
 }
 
 // Error returns the error provided to Cancel, or nil if no error has been provided.