Merge pull request #1300 from cpuguy83/fix_bridge_ep_panic

Fix panic calling `ep` instead of `endpoint`

libnetwork/drivers/bridge/bridge.go

@@ -1020,7 +1020,7 @@ func (d *driver) CreateEndpoint(nid, eid string, ifInfo driverapi.InterfaceInfo,
 	}
 
 	if err = d.storeUpdate(endpoint); err != nil {
-		return fmt.Errorf("failed to save bridge endpoint %s to store: %v", ep.id[0:7], err)
+		return fmt.Errorf("failed to save bridge endpoint %s to store: %v", endpoint.id[0:7], err)
 	}
 
 	return nil