vk: don't depend on current clamping values when compiling shader

Fog clamping values may change so the shader shouldn't depend on the
current value when compiling.
Fixes Red Dog Superior Firepower glitch.
Issue #1642

core/rend/vulkan/oit/oit_pipeline.cpp

@@ -144,7 +144,7 @@ void OITPipelineManager::CreatePipeline(u32 listType, bool autosort, const PolyP
 	OITShaderManager::FragmentShaderParams params = {};
 	params.alphaTest = listType == ListType_Punch_Through;
 	params.bumpmap = pp.tcw.PixelFmt == PixelBumpMap;
-	params.clamping = pp.tsp.ColorClamp && (pvrrc.fog_clamp_min.full != 0 || pvrrc.fog_clamp_max.full != 0xffffffff);
+	params.clamping = pp.tsp.ColorClamp;
 	params.insideClipTest = (pp.tileclip >> 28) == 3;
 	params.fog = config::Fog ? pp.tsp.FogCtrl : 2;
 	params.gouraud = pp.pcw.Gouraud;

core/rend/vulkan/pipeline.cpp

@@ -375,7 +375,7 @@ void PipelineManager::CreatePipeline(u32 listType, bool sortTriangles, const Pol
 	FragmentShaderParams params = {};
 	params.alphaTest = listType == ListType_Punch_Through;
 	params.bumpmap = pp.tcw.PixelFmt == PixelBumpMap;
-	params.clamping = pp.tsp.ColorClamp && (pvrrc.fog_clamp_min.full != 0 || pvrrc.fog_clamp_max.full != 0xffffffff);
+	params.clamping = pp.tsp.ColorClamp;
 	params.insideClipTest = (pp.tileclip >> 28) == 3;
 	params.fog = config::Fog ? pp.tsp.FogCtrl : 2;
 	params.gouraud = pp.pcw.Gouraud;