fs/ntfs3: Fix hidedotfiles mount option by reversing behaviour

Currently, the hidedotfiles mount option is behaving in the reverse
way of what would be expected: enabling it disables setting the
hidden attribute on files or directories with names starting with a
dot and disabling it enables the setting.

Reverse the behaviour of the hidedotfiles mount option so it matches
what is expected.

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