[epiphany] bookmark: Improve some assertions

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ceda45d402087e0250db98f8d8ff9c38be8d34cf
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Tue Nov 1 11:42:22 2016 -0500

    bookmark: Improve some assertions

 src/bookmarks/ephy-bookmark.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/bookmarks/ephy-bookmark.c b/src/bookmarks/ephy-bookmark.c
index ffe12fb..5d2a9fa 100644
--- a/src/bookmarks/ephy-bookmark.c
+++ b/src/bookmarks/ephy-bookmark.c
@@ -469,8 +469,8 @@ ephy_bookmark_bookmarks_sort_func (EphyBookmark *bookmark1,
   gint64 time1;
   gint64 time2;
 
-  g_assert (bookmark1 != NULL);
-  g_assert (bookmark2 != NULL);
+  g_assert (EPHY_IS_BOOKMARK (bookmark1));
+  g_assert (EPHY_IS_BOOKMARK (bookmark2));
 
   time1 = ephy_bookmark_get_time_added (bookmark1);
   time2 = ephy_bookmark_get_time_added (bookmark2);