wayland: Survive an unsupported buffer size

If cogl fails to create a texture from the client's given buffer,
mutter would raise a fatal error and terminate.

As a result, a broken client might kill gnome-shell/mutter and take the
entire Wayland session with it.

Instead of raising a fatal error in this case, log the cogl error
message and send the client an OOM error, so mutter/gnome-shell can
survive an unsupported buffer size.

https://bugzilla.gnome.org/show_bug.cgi?id=770387

src/wayland/meta-wayland-buffer.c

@@ -106,8 +106,10 @@ meta_wayland_buffer_ensure_texture (MetaWaylandBuffer *buffer)
 
   if (!texture)
     {
+      meta_warning ("Could not import pending buffer, ignoring commit: %s\n",
+                    catch_error->message);
       cogl_error_free (catch_error);
-      meta_fatal ("Could not import pending buffer, ignoring commit\n");
+      goto out;
     }
 
   buffer->texture = texture;