doc: fix metadata in go_mem.html

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5781053
diff --git a/doc/go_mem.html b/doc/go_mem.html
index 1d45dce..d4f3656 100644
--- a/doc/go_mem.html
+++ b/doc/go_mem.html
@@ -1,6 +1,6 @@
 <!--{
 	"Title": "The Go Memory Model",
-	"Subtitle": "Version of March 6, 2012"
+	"Subtitle": "Version of March 6, 2012",
 	"Path": "/ref/mem"
 }-->