c8d/import: Don't close compressed stream twice

The compressor is already closed a few lines below and there's no error
returns between so the defer is not needed.

Calling Close twice on a writerCloserWrapper is unsafe as it causes it
to put the same buffer to the pool multiple times.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

daemon/containerd/image_import.go

@@ -258,7 +258,6 @@ func compressAndWriteBlob(ctx context.Context, cs content.Store, compression arc
 	if err != nil {
 		return "", "", errdefs.InvalidParameter(err)
 	}
-	defer compressor.Close()
 
 	writeChan := make(chan digest.Digest)
 	// Start copying the blob to the content store from the pipe.