[libxml2] Fix build without reader but with pattern

[Nick Wellnhofer <nwellnhof src gnome org>]

commit f209e55107697159b49460f43ef74c735c4bfd5b
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Tue Jun 25 11:45:16 2019 +0200

    Fix build without reader but with pattern
    
    Broken by commit dbc6b55b.

 xmllint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/xmllint.c b/xmllint.c
index d84f084f..2bbe91d6 100644
--- a/xmllint.c
+++ b/xmllint.c
@@ -3758,7 +3758,7 @@ main(int argc, char **argv) {
        xmlSchemaFree(wxschemas);
     xmlRelaxNGCleanupTypes();
 #endif
-#ifdef LIBXML_PATTERN_ENABLED
+#if defined(LIBXML_READER_ENABLED) && defined(LIBXML_PATTERN_ENABLED)
     if (patternc != NULL)
         xmlFreePattern(patternc);
 #endif