1. find_first_bit API returns Size value if it doesn’t find any bit set.
This was causing VOICE AC counter to go high even for TID 0
2. Reset stats was not resetting the stats immediately
3. Added checks to avoid spurious stats increment
4. Detect data/mgmt pkt to avoid spurious stats increment
Change-Id: Ic9c5695fc7bdf58d1237e7e20bb79378a02a21f6