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