Fix typo in docs for New()

logger.go

@@ -58,7 +58,7 @@ func (mw *MutexWrap) Disable() {
 // `Out` and `Hooks` directly on the default logger instance. You can also just
 // instantiate your own:
 //
-//    var log = &Logger{
+//    var log = &logrus.Logger{
 //      Out: os.Stderr,
 //      Formatter: new(JSONFormatter),
 //      Hooks: make(LevelHooks),