fs/ntfs3: Fix various spelling mistakes

There is a spelling mistake in a ntfs_err error message. Also
fix various spelling mistakes in comments.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>