qcacmn: Fix multiple free of a single memory and memory leak in scan

MBSSID beacon support change 2371483 caused multiple free of
scan_list in failure cases. Also only memory for scan_list was
freed without freeing any scan entries in scan_list.
Fix multiple free of scan_list by multiple functions and free
each scan entry in scan_list before freeing scan_list memory itself.

Change-Id: I113391629f544b7accb9a4d1b7aaea11624e0d6e
CRs-Fixed: 2295311
1 file changed