layers: Add new module to stats script

Change-Id: Ic353c7bd1d0c9d067fa52d413b25a87f641c4747
diff --git a/layers/vk_validation_stats.py b/layers/vk_validation_stats.py
index ca30864..f34fb06 100755
--- a/layers/vk_validation_stats.py
+++ b/layers/vk_validation_stats.py
@@ -50,6 +50,7 @@
 'parameter_validation.cpp',
 'object_tracker.cpp',
 'image.cpp',
+'buffer_validation.cpp',
 'swapchain.cpp'
 ]
 header_file = 'vk_validation_error_messages.h'