x11: Trap XRandr errors when getting outputs during init and update

x11: Trap XRandr errors when getting outputs during init and update

We may try to update the XRR outputs and Crtcs when they're changing in
the server, and so we may get BadRROutput that we're currently not
handling properly.

As per this, use traps and check whether we got errors, and if we did
let's ignore the current output.

It's not required to call init_randr13() again because if we got errors
it's very likely that there's a change coming that will be notified at
next iteration during which we'll repeat the init actions.