Destroy surface by force when not destroying an extended surface
Destroy surface by force when not destroying an extended surface

As QWaylandSurface doesn't offer a public property stating if the surface
is extendeded (yet), let destroySurface() act like destroySurfaceByForce()
for non-extended (non-Qt) surfaces.

Change-Id: Ib8cb372b446404f744ebc07d1e2d8c68a39d97a7
Reviewed-by: Jan Arne Petersen <b1bf184240cd615d6163a9647416c253ae3b637c@kdab.com>
Reviewed-by: Andy Nichols <3d1e63b963f99f97839545621c6a9a8e2b2ab8fd@digia.com>

Tofee/qtwayland,locusf/qtwayland-1,ntanibata/qtwayland,locusf/qtwayland-1,locusf/qtwayland-1,locusf/qtwayland-1,Tofee/qtwayland,Tofee/qtwayland,ntanibata/qtwayland,ntanibata/qtwayland