Under marlin only files are listed

so no need to look after folder which could lead to false positif
For smoothieware the usage of M20 is not working for subfolder so use ls
instead and no need to use file cache

Author: luc-github

esp3d/esp3d.ino.nodemcu.bin

@@ -3408,13 +3408,13 @@ void handleSDFileList()
             jsonfile+="\",\"size\":\"";
             LOG(String(i+1));
             LOG(sname);
-            if (sname[0] == '/' || sname[sname.length()-1]=='/') {
+          /*  if (sname[0] == '/' || sname[sname.length()-1]=='/') {
                 jsonfile+="-1";
                 LOG(" -1");
-            } else {
+            } else {*/
                 //nothing to add
                 jsonfile+="";
-            }
+           // }
             LOG("\r\n");
 #endif
             jsonfile+="\"}";