UKSM: Move is_full_zero() function

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: Move ksm releated functions

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: Remove commented get_current_neg_ratio()

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
UKSM: Clenaups

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>