mac80211: fix mesh endianness sparse warnings and unmark it as broken

This patch fixes all the mesh related endianness warnings reported by sparse. As
they were the reason why Johannes marked mesh as BROKEN, that flag has been
removed.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>