sampler: don't apply picmip unless it's set in config

src/overlay_params.cpp

@@ -652,7 +652,7 @@ parse_overlay_config(struct overlay_params *params,
    params->round_corners = 0;
    params->battery_color =0xff9078;
    params->fsr_steam_sharpness = -1;
-   params->picmip = 0;
+   params->picmip = -17;
    params->af = -1;
    params->preset = -1;
 

src/vulkan.cpp

@@ -1941,8 +1941,9 @@ static VkResult overlay_CreateSampler(
    struct device_data *device_data = FIND(struct device_data, device);
    auto params = device_data->instance->params;
 	VkSamplerCreateInfo sampler = *pCreateInfo;
-   
-   sampler.mipLodBias = params.picmip;
+
+   if (params.picmip > -17 && params.picmip < 17)
+      sampler.mipLodBias = params.picmip;
 
    if (params.af > 0){
       sampler.anisotropyEnable = VK_TRUE;