Lot of checks in Tx completion path are for special handlings
such as when ol stats are enabled some protective debug checks etc..
Add a logic to fast free of buffer at transmit completion.
If extended stats not enabled(Typically needed for enterprise cases)
do the buffer free faster. This is controlled through a flag.
Change-Id: I04873b5e3643d8e93e5b248fcaf23504dcb7624f