clientv3: Check the error return from Write in v3Manager#Status (#11837)
clientv3: Check the error return from Write in v3Manager#Status (#11837)

Signed-off-by: Ted Yu <22f3e725b314afeca4d45e12683c560674029d21@gmail.com>
mkumatag/etcd,rnaveiras/etcd,li-ang/etcd,cockroachdb/etcd,mkumatag/etcd,gyuho/etcd,ajityagaty/etcd,gyuho/etcd,mqliang/etcd,ajityagaty/etcd,rnaveiras/etcd,etcd-io/etcd,dannysauer/etcd,li-ang/etcd,etcd-io/etcd,mqliang/etcd,mqliang/etcd,ajityagaty/etcd,dannysauer/etcd,rnaveiras/etcd,etcd-io/etcd,coreos/etcd,mkumatag/etcd,coreos/etcd,cockroachdb/etcd