qcacld-3.0: Release vdev ref gracefully
In function hdd_nan_sr_concurrency_update, the FOR iteration has
released the vdev ref if is_sr_enabled is false, but it does not
set sta_vdev to NULL. It causes the last sta_vdev ref count release
again and this causes issue of releasing ref count which was not taken.
Change-Id: Ia218073b4ef2508cd78370bb4236790df9b5ee4f
CRs-Fixed: 3363355