net: Use NET_XMIT_SUCCESS where possible.

This is based on work originally done by Patric McHardy.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/sched/sch_atm.c
Simple merge

diff --cc net/sched/sch_sfq.c
Simple merge

diff --cc net/sched/sch_tbf.c
Simple merge

diff --cc net/sched/sch_teql.c
Simple merge