st/nine: Avoid useless updates in SetSamplerState
st/nine: Avoid useless updates in SetSamplerState

Check for redundant settings

Signed-off-by: Axel Davy <2b6ef604b998fb81662f85c329e4fc020eae8e5d@ens.fr>
Reviewed-by: David Heidelberg <aa743a0aaec8f7d7a1f01442503957f4d7a2d634@ixit.cz>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler