reftable: remove outdated comment

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I41a7d9934d53553b5f81f40ff9d663378676ac5d

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileReftableStack.java

@@ -285,9 +285,6 @@ public class FileReftableStack implements AutoCloseable {
 		}
 
 		if (!success) {
-			// TODO: should reexamine the 'refs' file to see if it was the same
-			// if it didn't change, then we must have corruption. If it did,
-			// retry.
 			throw new LockFailedException(stackPath);
 		}