qcacmn: Fix QDF assert in wlan_abort_scan if vdev is NULL

If vdev is NULL calling calling wlan_objmgr_vdev_release_ref
cause assert.

To fix avoid calling wlan_objmgr_vdev_release_ref if vdev is NULL.

Change-Id: I8bd40ac27a6733177ac55c791c7c3ddfe5bbba30
CRs-Fixed: 1095299
1 file changed