evas-wayland-shm: Compare hidden flag during reconfigure

evas-wayland-shm: Compare hidden flag during reconfigure

Small patch to compare if the hidden flag being passed in is the same
as the one stored in Outbuf. With the addition of xdg_shell v6
support, we cannot commit a surface with an existing buffer until the
surface has been configured. In order to facilitate this, we will use
the 'hidden' flag so that any surface_post does not actually attach a
buffer unless configure has already been handled on the surface.

ref T5090

Signed-off-by: Chris Michael <cp.michael@samsung.com>