vulkan.h: V120 -- Tighten spec around VkMemoryRequirements

Moved the HOST_LOCAL memory property.
diff --git a/layers/screenshot.cpp b/layers/screenshot.cpp
index 19e8ed3..313bb72 100644
--- a/layers/screenshot.cpp
+++ b/layers/screenshot.cpp
@@ -138,8 +138,7 @@
         0,     // allocationSize, queried later
         (VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
             VK_MEMORY_PROPERTY_HOST_UNCACHED_BIT |
-            VK_MEMORY_PROPERTY_HOST_WRITE_COMBINED_BIT |
-            VK_MEMORY_PROPERTY_PREFER_HOST_LOCAL)
+            VK_MEMORY_PROPERTY_HOST_WRITE_COMBINED_BIT)
     };
     const VkCmdBufferCreateInfo createCommandBufferInfo = {
         VK_STRUCTURE_TYPE_CMD_BUFFER_CREATE_INFO,