tools/ceph_dedup: add modelines for emacs and vim

add modelines for emacs and vim so that the source code is formatted
with expected alignment even if the editor's default setting is not
match with the expected settings.

Signed-off-by: Kefu Chai <[email protected]>

Author: tchaikov

src/tools/ceph_dedup/ceph_dedup_daemon.cc

@@ -1,3 +1,6 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
 #include "common.h"
 #include "log/Log.h"