wireless: fix fatal kernel-doc error + warning in mac80211.h

Fix new kernel-doc Error and Warning in <net/mac80211.h>:

Error(linux-2.6.39-git5/include/net/mac80211.h:550): cannot understand prototype: 'struct ieee80211_sched_scan_ies '
Warning(linux-2.6.39-git5/include/net/mac80211.h:2289): No description found for parameter 'sta'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>