patch d114f399 in mainline.

The previous IW_SCAN_THIS_ESSID patch left a hole allowing scan
requests on interfaces in inappropriate modes.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>