layers: Fix Dota 2 crash in draw_state layer

Memsetting STL vectors again -- added default constructor to struct.
diff --git a/layers/draw_state.cpp b/layers/draw_state.cpp
index a5b42bd..5730750 100644
--- a/layers/draw_state.cpp
+++ b/layers/draw_state.cpp
@@ -2124,7 +2124,6 @@
                     "Out of memory while attempting to allocate LAYOUT_NODE in vkCreateDescriptorSetLayout()"))
                 return VK_ERROR_VALIDATION_FAILED;
         }
-        memset(pNewNode, 0, sizeof(LAYOUT_NODE));
         memcpy((void*)&pNewNode->createInfo, pCreateInfo, sizeof(VkDescriptorSetLayoutCreateInfo));
         pNewNode->createInfo.pBinding = new VkDescriptorSetLayoutBinding[pCreateInfo->bindingCount];
         memcpy((void*)pNewNode->createInfo.pBinding, pCreateInfo->pBinding, sizeof(VkDescriptorSetLayoutBinding)*pCreateInfo->bindingCount);
diff --git a/layers/draw_state.h b/layers/draw_state.h
index db05bac..a1fd1d3 100755
--- a/layers/draw_state.h
+++ b/layers/draw_state.h
@@ -170,7 +170,10 @@
     vector<VkDescriptorType>        descriptorTypes; // Type per descriptor in this layout to verify correct updates
     vector<VkShaderStageFlags>      stageFlags; // stageFlags per descriptor in this layout to verify correct updates
     unordered_set<uint32_t>         bindings;
+    // Default constructor
+    _LAYOUT_NODE():layout{},createInfo{},startIndex(0),endIndex(0),dynamicDescriptorCount(0) {};
 } LAYOUT_NODE;
+
 // Store layouts and pushconstants for PipelineLayout
 struct PIPELINE_LAYOUT_NODE {
     vector<VkDescriptorSetLayout>  descriptorSetLayouts;