fix(littlefs): Use VFSImpl::exists() to avoid false error log

Author: BlueAndi

Diff for: libraries/LittleFS/src/LittleFS.cpp

@@ -33,16 +33,10 @@ class LittleFSImpl : public VFSImpl {
 public:
   LittleFSImpl();
   virtual ~LittleFSImpl() {}
-  virtual bool exists(const char *path);
 };
 
 LittleFSImpl::LittleFSImpl() {}
 
-bool LittleFSImpl::exists(const char *path) {
-  File f = open(path, "r", false);
-  return (f == true);
-}
-
 LittleFSFS::LittleFSFS() : FS(FSImplPtr(new LittleFSImpl())), partitionLabel_(NULL) {}
 
 LittleFSFS::~LittleFSFS() {