Fix the empty logs

seven.diff

diff --git a/main.go b/main.go
index c45418b..dd7d1ef 100644
--- a/main.go
+++ b/main.go
@@ -31,9 +31,10 @@ func sink(ctx context.Context, values <-chan string) {
 			log.Print(ctx.Err().Error())
 			return
 		case val, ok := <-values:
-			log.Println(val)
 			if ok {
 				log.Printf("sink: %s", val)
+			} else {
+				return
 			}
 		}
 	}