Remove unnecessary cast

Change-Id: I517b2d0a53e425bc8cb7bb1fbc1f8be0bf11c256

src/main/java/com/googlesource/gerrit/plugins/xdocs/XDocLoader.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/xdocs/XDocLoader.java b/src/main/java/com/googlesource/gerrit/plugins/xdocs/XDocLoader.java
index d0c62ad..c2fab74 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/xdocs/XDocLoader.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/xdocs/XDocLoader.java
@@ -216,7 +216,7 @@
       Repository repo, ObjectLoader loader, Project.NameKey project,
       String path, ObjectId revId) throws IOException {
     try (InputStream raw = loader.openStream()) {
-      return ((StreamFormatter) f).format(project.get(), path, revId.getName(),
+      return f.format(project.get(), path, revId.getName(),
           getAbbrRevId(repo, revId), getFormatterConfig(formatterName), raw);
     }
   }