[tepl] pango: add missing g_return

[Sébastien Wilmet <swilmet src gnome org>]

commit be6886da100939299309d8ab7d5300f314c76038
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Oct 29 22:15:32 2020 +0100

    pango: add missing g_return

 tepl/tepl-pango.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/tepl/tepl-pango.c b/tepl/tepl-pango.c
index 54e3ca8..7ed0009 100644
--- a/tepl/tepl-pango.c
+++ b/tepl/tepl-pango.c
@@ -92,6 +92,8 @@ tepl_pango_font_description_to_css (const PangoFontDescription *desc)
   GString *s;
   PangoFontMask set;
 
+  g_return_val_if_fail (desc != NULL, NULL);
+
   s = g_string_new ("");
 
   set = pango_font_description_get_set_fields (desc);