Decompressors: check for write errors in unlzo.c

From: Lasse Collin <lasse.collin@xxxxxxxxxxx>

The return value of flush() is not checked in unlzo().  This means that
the decompressor won't stop even if the caller doesn't want more data.
This can happen e.g.  with a corrupt LZO-compressed initramfs image.

Signed-off-by: Lasse Collin <lasse.collin@xxxxxxxxxxx>
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/common/unlzo.c
+++ b/xen/common/unlzo.c
@@ -202,8 +202,8 @@ STATIC int INIT unlzo(u8 *input, unsigne
 			}
 		}
 
-		if (flush)
-			flush(out_buf, dst_len);
+		if (flush && flush(out_buf, dst_len) != dst_len)
+			goto exit_2;
 		if (output)
 			out_buf += dst_len;
 		if (posp)