fs/ntfs3: Use _le variants of bitops functions

The functions from bitops.h already have _le variants so use them to
prevent invalid reads/writes of the bitmap on big endian systems.

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