cfg80211: issue netlink notification when scan starts

To ease multiple apps working together smoothly,
send a notification when a scan is started.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --cc net/wireless/nl80211.c
Simple merge

diff --cc net/wireless/nl80211.h
Simple merge

diff --cc net/wireless/scan.c
Simple merge