Xephyr: restore cursor visibility

Xephyr: restore cursor visibility

  Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=69388

Commit c100211034ab69ce453a1644fb61c6808d7e3eda (dix: only show the cursor
if a window defines one (#58398)) broke the default cursor behaviour in
Xephyr (unless run with -retro). Restore the default cursor visibility
so that '-retro' or '-host-cursor' are not needed to have a visible
cursor.

Signed-off-by: Michele Baldessari <michele@acksyn.org>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
as of ba387cf21f7d95987211f75d8024601e7d64e322 "ephyr: Use host (HW) cursors
by default." this only applies if -sw-cursor is given on the cmdline.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>