switch DscpPolicyTracker from U32 to S32

In practice these are tiny indexes into a small array, see:
  packages/modules/Connectivity/bpf_progs/dscpPolicy.h
  #define MAX_POLICIES 16
So there is no need to complicate things...

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Iac3ddd3fc726b1643b1aad42e40f97ea12cebf29
(cherry picked from commit bdf970240e6a6ae02670cbaaec68bfa43e45ae6d)
Merged-In: Iac3ddd3fc726b1643b1aad42e40f97ea12cebf29
1 file changed