move guard higher and add comment

Author: td-tomasz

lib/winston/transports/file.js

@@ -155,11 +155,13 @@ module.exports = class File extends TransportStream {
       debug('logged %s %s', this._size, output);
       this.emit('logged', info);
 
-      // Do not attempt to rotate files while opening
-      if (this._opening) {
+      // Do not attempt to rotate files while rotating
+      if (this._rotate) {
         return;
       }
-      if (this._rotate) {
+
+      // Do not attempt to rotate files while opening
+      if (this._opening) {
         return;
       }