Yet another permission denied

[elibarzilay]

Recently wsld started failing on one of my machines with an obscure permission denied message. After fumbling with it for a while, I figured out that this is an issue of not being able to remove /tmp/.X11-unix/X0, and sudo-removing it made things good again.

Two things are relevant here:

1. I think that this has started recently because I did a new ubuntu setup -- and it now starts wslg as part of the setup, which means that you're left with a root-owned directory.
2. It would therefore be nice to revise the code a bit and say what exactly caused the error rather than a vague "permission denied" -- it would at least save me a couple of hours trying to run in random directions.

I think that the offending code is

wsld/client/src/x11socket.rs

Lines 66 to 67 in c224798

	let _ = std::fs::create_dir_all("/tmp/.X11-unix");
	let _ = std::fs::remove_file(&name);

which looks like it's ignoring the prospect of not being able to write that, and fails in a generic way rather that just telling you what went wrong.

(This is probably a duplicate of a few other issues, and adding an error would mean not spending time telling people about removing the files :)