fs/ntfs3: Use clamp/max macros instead of comparisons

We can make code little more readable by using kernel macros clamp/max.

This were found with kernel included Coccinelle minmax script.

Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>