mac80211: fix compilation of mesh (although its disabled)

Mesh is currently disabled on mac80211, its marked
as broken. This patch gets it to compile though,
to account for the mac80211 workqueue changes.
There was a simple typo in the patches for mesh
for the workqueue migration, but we never compile
tested it as we couldn't even select mesh as its
broken. Lets at least let it compile for those
interested in getting it fixed.

Reported-by: Pat Erley <pat-lkml@erley.org>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>