When wmi_roam_synch_frame_event receieved from firmware, memory is
malloced to save probe rsp/reassoc req/reassoc rsp once extract event,
when copied to vdev rso_cfg->roam_sync_frame_ind, memory is malloc again,
and original memory isn't freed, memory leak happens.
To fix it, assure memory is only malloced once to save
probe rsp/reassoc req/reassoc rsp when handle wmi_roam_synch_frame_event.
Change-Id: I6b31378bcf624547fca9fd858268252fd22f533d
CRs-Fixed: 3107576
07775e1204