fs/ntfs3: Add functions to modify LE bitmaps

__bitmap_set/__bitmap_clear only works with bitmaps in CPU order.
Define a variant of these functions in ntfs3 to handle modifying bitmaps
read from the filesystem.

Signed-off-by: Thomas Kühnel <thomas.kuehnel@avm.de>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>