[libxml2] Fix memory leak in LZMA decompressor

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 07e227ed00d0fb787c06cf03069b2904e692e770
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Sep 7 18:55:46 2017 +0200

    Fix memory leak in LZMA decompressor

 xzlib.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/xzlib.c b/xzlib.c
index f43632b..8bafbd3 100644
--- a/xzlib.c
+++ b/xzlib.c
@@ -797,6 +797,8 @@ __libxml2_xzclose(xzFile file)
         xmlFree(state->in);
     }
     xmlFree(state->path);
+    if ((state->msg != NULL) && (state->err != LZMA_MEM_ERROR))
+        xmlFree(state->msg);
     ret = close(state->fd);
     xmlFree(state);
     return ret ? ret : LZMA_OK;