[PATCH] mac80211: Fix SSID matching in AP selection

The length of the SSID desired should also be compared in addition to
the memcmp of the SSIDs.

Thanks to Andrea Merello <andreamrl@tiscali.it> for finding this issue.

Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>