[gtk] testtreelistmodel: Don't use non-standard function

[Daniel Boles <dboles src gnome org>]

commit 18199a3cef0f12c94f8cc9247be4352cfb85b692
Author: Daniel Boles <dboles src gmail com>
Date:   Wed Oct 24 19:48:45 2018 +0100

    testtreelistmodel: Don't use non-standard function
    
    as per efd3758f6a779041ff552cb4c5163446fd951368 strcasecmp() is not a C
    standard thing (not that we bothered including any header for it anyway)
    and so this test failed to build on Windows with Microsoft Visual C.

 tests/testtreelistmodel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/testtreelistmodel.c b/tests/testtreelistmodel.c
index ad9f0f4c59..88f219797b 100644
--- a/tests/testtreelistmodel.c
+++ b/tests/testtreelistmodel.c
@@ -131,7 +131,7 @@ compare_files (gconstpointer first,
   first_path = g_file_get_path (first_file);
   second_path = g_file_get_path (second_file);
 
-  result = strcasecmp (first_path, second_path);
+  result = g_ascii_strcasecmp (first_path, second_path);
 
   g_free (first_path);
   g_free (second_path);