[libxml2] Fix memory leak in xmlXIncludeIncludeNode error paths

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 5725c1153a74d997aa8ea8547574c049b040d5cb
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Wed Jun 10 15:11:40 2020 +0200

    Fix memory leak in xmlXIncludeIncludeNode error paths
    
    Found with libFuzzer and ASan.

 xinclude.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/xinclude.c b/xinclude.c
index baeb8dbca..461c1a558 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -2238,6 +2238,7 @@ xmlXIncludeIncludeNode(xmlXIncludeCtxtPtr ctxt, int nr) {
                           XML_XINCLUDE_MULTIPLE_ROOT,
                       "XInclude error: would result in multiple root nodes\n",
                           NULL);
+            xmlFreeNodeList(list);
            return(-1);
        }
     }
@@ -2265,6 +2266,7 @@ xmlXIncludeIncludeNode(xmlXIncludeCtxtPtr ctxt, int nr) {
            xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref,
                           XML_XINCLUDE_BUILD_FAILED,
                           "failed to build node\n", NULL);
+            xmlFreeNodeList(list);
            return(-1);
        }
        end->type = XML_XINCLUDE_END;