VmaBlockVector::Defragment: Minor fix for case when VMA_DEBUG_DETECT_CORRUPTION != 0.

Author: adam-sawicki-a

src/vk_mem_alloc.h

@@ -12119,9 +12119,13 @@ void VmaBlockVector::Defragment(
 
     const VkMemoryPropertyFlags memPropFlags =
         m_hAllocator->m_MemProps.memoryTypes[m_MemoryTypeIndex].propertyFlags;
+    const bool isHostVisible = (memPropFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0;
+    const bool isHostCoherent = (memPropFlags & VK_MEMORY_PROPERTY_HOST_COHERENT_BIT) != 0;
+
     const bool canDefragmentOnCpu = maxCpuBytesToMove > 0 && maxCpuAllocationsToMove > 0 &&
-        (memPropFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0;
-    const bool canDefragmentOnGpu = maxGpuBytesToMove > 0 && maxGpuAllocationsToMove > 0;
+        isHostVisible;
+    const bool canDefragmentOnGpu = maxGpuBytesToMove > 0 && maxGpuAllocationsToMove > 0 &&
+        (VMA_DEBUG_DETECT_CORRUPTION == 0 || !(isHostVisible && isHostCoherent));
 
     // There are options to defragment this memory type.
     if(canDefragmentOnCpu || canDefragmentOnGpu)