The previously used 10 second timeout allowed only two scan attempts
(five seconds between scans) and it was possible to hit a failure every
now and then when running under heavy load and the Probe Response frame
got delayed by 40 ms or so twice in a row. Add more time for one more
scan attempt to reduce the likelihood of this happening.
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>