[libxslt] Check for null pointer before calling freelocale

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 7fd30eba2f0f96be90a0741e051099d55970bded
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Sat Dec 19 16:34:47 2020 +0100

    Check for null pointer before calling freelocale

 libxslt/xsltlocale.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/libxslt/xsltlocale.c b/libxslt/xsltlocale.c
index c69735cd..39980f8d 100644
--- a/libxslt/xsltlocale.c
+++ b/libxslt/xsltlocale.c
@@ -346,7 +346,8 @@ xsltDefaultRegion(const xmlChar *localeName) {
 void
 xsltFreeLocale(xsltLocale locale) {
 #ifdef XSLT_LOCALE_POSIX
-    freelocale(locale);
+    if (locale != NULL)
+        freelocale(locale);
 #endif
 }