doc/articles/image_draw.html: fix circle example
It was showing the same snippet twice instead of the type definition and snippet.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/5875045
diff --git a/doc/articles/image_draw.html b/doc/articles/image_draw.html
index 848b659..b1adbc5 100644
--- a/doc/articles/image_draw.html
+++ b/doc/articles/image_draw.html
@@ -178,7 +178,7 @@
 <code>r</code>:
 </p>
 
-{{code "/doc/progs/image_draw.go" `/CIRCLE/` `/STOP/`}}
+{{code "/doc/progs/image_draw.go" `/CIRCLESTRUCT/` `/STOP/`}}
 {{code "/doc/progs/image_draw.go" `/CIRCLE2/` `/STOP/`}}
   
 <p>
diff --git a/doc/progs/image_draw.go b/doc/progs/image_draw.go
index f3400b6..2cc5c63 100644
--- a/doc/progs/image_draw.go
+++ b/doc/progs/image_draw.go
@@ -117,7 +117,7 @@
 	// STOP OMIT
 }
 
-//CIRCLE OMIT
+//CIRCLESTRUCT OMIT
 type circle struct {
 	p image.Point
 	r int
@@ -139,4 +139,4 @@
 	return color.Alpha{0}
 }
 
-//STOP
+//STOP OMIT