Fix transitions for image_download and activation

Change-Id: I713ada52eef9d275c7d7596026e178c7382e8335
diff --git a/vendor/golang.org/x/net/http2/client_conn_pool.go b/vendor/golang.org/x/net/http2/client_conn_pool.go
index f4d9b5e..3a67636 100644
--- a/vendor/golang.org/x/net/http2/client_conn_pool.go
+++ b/vendor/golang.org/x/net/http2/client_conn_pool.go
@@ -107,6 +107,7 @@
 
 // dialCall is an in-flight Transport dial call to a host.
 type dialCall struct {
+	_    incomparable
 	p    *clientConnPool
 	done chan struct{} // closed when done
 	res  *ClientConn   // valid after done is closed
@@ -180,6 +181,7 @@
 }
 
 type addConnCall struct {
+	_    incomparable
 	p    *clientConnPool
 	done chan struct{} // closed when done
 	err  error
@@ -200,12 +202,6 @@
 	close(c.done)
 }
 
-func (p *clientConnPool) addConn(key string, cc *ClientConn) {
-	p.mu.Lock()
-	p.addConnLocked(key, cc)
-	p.mu.Unlock()
-}
-
 // p.mu must be held
 func (p *clientConnPool) addConnLocked(key string, cc *ClientConn) {
 	for _, v := range p.conns[key] {