Fix broken link (docker#4047)

Author: Misty Stanley-Jones

engine/tutorials/dockervolumes.md

@@ -26,7 +26,7 @@ Data volumes provide several useful features for persistent or shared data:
 - Volumes are initialized when a container is created. If the container's
   parent image contains data at the specified mount point, that existing data is
   copied into the new volume upon volume initialization. (Note that this does
-  not apply when [mounting a host directory](#mount-a-host-directory-as-a-data-volume).)
+  not apply when [mounting a host directory](#mount-a-host-file-as-a-data-volume).)
 - Data volumes can be shared and reused among containers.
 - Changes to a data volume are made directly.
 - Changes to a data volume will not be included when you update an image.