awslogs & archive: prevent 2 goroutine leaks in test functions

Signed-off-by: Ziheng Liu <lzhfromustc@gmail.com>

daemon/logger/awslogs/cloudwatchlogs_test.go

@@ -345,7 +345,7 @@ func TestLogNonBlockingBufferFull(t *testing.T) {
 		logNonBlocking: true,
 	}
 	stream.messages <- &logger.Message{}
-	errorCh := make(chan error)
+	errorCh := make(chan error, 1)
 	started := make(chan bool)
 	go func() {
 		started <- true

pkg/archive/archive_test.go

@@ -217,7 +217,7 @@ func TestCmdStreamLargeStderr(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Failed to start command: %s", err)
 	}
-	errCh := make(chan error)
+	errCh := make(chan error, 1)
 	go func() {
 		_, err := io.Copy(ioutil.Discard, out)
 		errCh <- err