remove stray unlock

connectionpool.go

@@ -241,7 +241,6 @@ func (p *policyConnPool) addHost(host *HostInfo) {
 	// TODO: policy should not have conns, it should have hosts and return a host
 	// iter which the pool will use to serve conns
 	p.hostPolicy.AddHost(host)
-	p.mu.Unlock()
 }
 
 func (p *policyConnPool) removeHost(addr string) {