Update hw_batching.c

HWR_ProcessPolygon()'s shader parameter was renamed to shader_target

src/hardware/hw_batching.c

@@ -134,7 +134,7 @@ void HWR_ProcessPolygon(FSurfaceInfo *pSurf, FOutVector *pOutVerts, FUINT iNumPt
 			DIGEST(hash, pSurf->PolyColor.rgba);
 			if (cv_glshaders.value && gl_shadersavailable)
 			{
-				DIGEST(hash, shader);
+				DIGEST(hash, shader_target);
 				DIGEST(hash, pSurf->TintColor.rgba);
 				DIGEST(hash, pSurf->FadeColor.rgba);
 				DIGEST(hash, pSurf->LightInfo.light_level);