[FASTFAT] Only initialize directory cache on use.

This avoids initializing cache directly on directory
open/create.
The advantage is we reduce the load on cache manager
and on memory manager by avoiding creating everytime
a stream file object, and initializing cache for it.

This will avoid initializing cache for started
applications 'current directory' which is just opened
for having a valid handle but no read/write is performed
in it, by default.

This is a step forward for autochk.

CORE-14629

drivers/filesystems/fastfat/create.c

@@ -951,7 +951,7 @@ VfatCreateFile(
                                                &pFcb->entry.Fat.UpdateTime);
                 }
 
-                VfatUpdateEntry(pFcb, vfatVolumeIsFatX(DeviceExt));
+                VfatUpdateEntry(DeviceExt, pFcb);
             }
 
             ExAcquireResourceExclusiveLite(&(pFcb->MainResource), TRUE);