[libxml2] Fix memory leak in xmlParseCatalogFile

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 2510f43cbad2532adc2ea0b362021eb1b4eea561
Author: David King <amigadave amigadave com>
Date:   Wed Jul 14 14:03:44 2021 +0100

    Fix memory leak in xmlParseCatalogFile
    
    Found by Coverity.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1938806

 catalog.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/catalog.c b/catalog.c
index effbb2e6..6535f85c 100644
--- a/catalog.c
+++ b/catalog.c
@@ -915,6 +915,7 @@ xmlParseCatalogFile(const char *filename) {
 
     inputStream = xmlNewInputStream(ctxt);
     if (inputStream == NULL) {
+       xmlFreeParserInputBuffer(buf);
        xmlFreeParserCtxt(ctxt);
        return(NULL);
     }