Daily `arc lint --take CLANGFORMAT`

Reviewed By: zertosh

Differential Revision: D24188387

fbshipit-source-id: a540cf6db895dda48723492aa843bf32d66011f3

folly/tracing/AsyncStack.h

@@ -173,7 +173,7 @@ namespace folly {
 struct AsyncStackRoot;
 struct AsyncStackFrame;
 namespace detail {
-  class ScopedAsyncStackRoot;
+class ScopedAsyncStackRoot;
 }
 
 // Get access to the current thread's top-most AsyncStackRoot.