mac80211: don't reconfigure sched scan in case of wowlan

Scheduled scan has to be reconfigured only if wowlan wasn't
configured, since otherwise it should continue to run (with
the 'any' trigger) or be aborted.

The current code will end up asking the driver to start a new
scheduled scan without stopping the previous one, and leaking
some memory (from the previous request.)

Fix this by doing the abort/restart under the proper conditions.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>