In the api target_if_nan_set_vdev_feature_config (),
vdev is not validated before sending vdev set param cmd
to FW which results in crash for invalid vdev.
Validate vdev in the api target_if_nan_set_vdev_feature_config()
before sending vdev set param cmd.
Change-Id: I70ee56ae3c78f466c3757671c95b449925bb9fd2
CRs-Fixed: 3546457