Add image size calcuations into the script

Change-Id: Ide13a873982bae21e2b8735a235389a660abd592
diff --git a/core/Makefile b/core/Makefile
index 8d6fab7..af233f1 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -595,6 +595,7 @@
 define calculate-userimage-ext-size
   @echo Calculating image size...
   @find $(1) -type f | xargs du -k | sort -gr > $(PRODUCT_OUT)/imagesize-report.txt
+  @du -s -h -k $(1)
 endef
 
 # $(1): src directory