[NTFS] - Add some fixes and improvements to create.c, dirctl.c and fcb.c from CR-123:
-NtfsOpenFile() - Replace an ExFreePool() with ExFreePoolWithTag().
-NtfsCreateFile() - Fix broken cast with BooleanFlagOn() macro.
-NtfsAddFilenameToDirectory() - Remove an extra cast. Return an error if we fail to allocate I30IndexRoot.
-NtfsGetNextPathElement(), NtfsWSubString(), NtfsGetFCBForFile() - Use PCWSTR in place of const PWCHAR or PWCHAR where it makes sense.
svn path=/branches/GSoC_2016/NTFS/; revision=75281