[update_engine] Update to use not-hideously-old logging API from chrome

filesystem_iterator.cc

Index: filesystem_iterator.cc
diff --git a/filesystem_iterator.cc b/filesystem_iterator.cc
index 9d98dea92386a16202abaf308f8363bc7e70f1dc..af5f20930ab37beb5853f02103d0e50a325c8b60 100644
--- a/filesystem_iterator.cc
+++ b/filesystem_iterator.cc
@@ -9,7 +9,7 @@
 #include <set>
 #include <string>
 #include <vector>
-#include "chromeos/obsolete_logging.h"
+#include "base/logging.h"
 #include "update_engine/utils.h"
 
 using std::set;