[gnome-builder] libide: fix "non-void function should return a value"

[Christian Hergert <chergert src gnome org>]

commit 3803b35757cc4d63acd14497f6e825c42517415a
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Fri Apr 17 00:28:17 2015 +0800

    libide: fix "non-void function should return a value"
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747998

 libide/ide-project-files.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/libide/ide-project-files.c b/libide/ide-project-files.c
index 7f9568d..49f8690 100644
--- a/libide/ide-project-files.c
+++ b/libide/ide-project-files.c
@@ -112,8 +112,8 @@ ide_project_files_find_file (IdeProjectFiles *self,
   gchar *path;
   gsize i;
 
-  g_return_if_fail (IDE_IS_PROJECT_FILES (self));
-  g_return_if_fail (G_IS_FILE (file));
+  g_return_val_if_fail (IDE_IS_PROJECT_FILES (self), NULL);
+  g_return_val_if_fail (G_IS_FILE (file), NULL);
 
   item = IDE_PROJECT_ITEM (self);
   context = ide_object_get_context (IDE_OBJECT (self));