fs/ntfs3: Rename hidedotfiles mount option to hide_dot_files

The hidedotfiles mount option provides the same functionality as
the NTFS-3G hide_dot_files mount option. As such, it should be
named the same for compatibility with NTGS-3G.

Rename the hidedotfiles to hide_dot_files for compatbility with
NTFS-3G.

Signed-off-by: Daniel Pinto <danielpinto52@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>