Revert "mac80211: Use IWEVASSOCREQIE instead of IWEVCUSTOM"

This reverts commit 087d833e5a9f67ba933cb32eaf5a2279c1a5b47c, which was
reported to break wireless at least in some combinations with 32bit user
space and a 64bit kernel.  Alex Williamnson bisected it to this commit.

Reported-and-bisected-by: Alex Williamson <alex.williamson@hp.com>
Acked-by: John W. Linville <linville@tuxdriver.com>
Cc: David Miller <davem@davemloft.net>
Cc: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>