st/nine: Fix useless swapchain init checks
st/nine: Fix useless swapchain init checks

In NineDevice9_SetDefaultState we can assume the
implicit swapchain is properly initialized.

Signed-off-by: Axel Davy <2b6ef604b998fb81662f85c329e4fc020eae8e5d@ens.fr>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler