embed: Modify the comments to be more precise.

embed/etcd.go

@@ -743,7 +743,7 @@ func (e *Etcd) serveClients() (err error) {
 		}))
 	}
 
-	// start client servers in a goroutine
+	// start client servers in each goroutine
 	for _, sctx := range e.sctxs {
 		go func(s *serveCtx) {
 			e.errHandler(s.serve(e.Server, &e.cfg.ClientTLSInfo, h, e.errHandler, gopts...))