This function hasn't been used since the removal of iwmc3200wifi
in 2012. It also appears to have a bug when qos=True, since then
it'll copy uninitialized stack memory to the SKB.

Just remove the function entirely.
Reported-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>