fullscreen-shell: Fix modeset on transformed outputs
fullscreen-shell: Fix modeset on transformed outputs

Previously, we blindly created a mode for the output based on surface size
and completely ignoring the output transform.  This caused modesets to fail
on outputs that were transformed by 90 or 270 degrees.  We should be
swapping the width and the height in this case.

Reviewed-by: Derek Foreman <2f97e0f0bc172406aab8ccd42dab54c95bab8759@osg.samsung.com>
Tested-by: Derek Foreman <2f97e0f0bc172406aab8ccd42dab54c95bab8759@osg.samsung.com>

xorgy/weston,giucam/weston,krezovic/weston,jonnylamb/weston,Tarnyko/weston-xdg_surface_present,giucam/weston,Gnurou/weston,kwm81/weston,krezovic/weston,udoprog/weston,xorgy/weston,jonnylamb/weston,sir-murray/weston,sir-murray/weston,Fantu/compositor-spice,Fantu/compositor-spice,kwm81/weston,Fantu/compositor-spice,Tarnyko/weston-xdg_surface_present,Gnurou/weston,udoprog/weston