qcacmn: Resolve null pointer dereference issue in flush txdesc

On Flushing txdesc resource on pdev detach caused null ptr
issue, resolved it by adding dummy function to not free desc
resources for mcl, as it is freed in vdev detach.

Change-Id: I9ab777571623c926b4ecbf9c95ba0837101eba26
CRs-Fixed: 2179488
1 file changed