[CMFileManager] Fix the filemanager can copy parent folder to child folder

Procedures
1.Go into filemanager and select a directory(such as Music).
2.enter the Music and copy the folder.

The filemanager stay in "copying" interface.

Change-Id: I9a765d1d89c4736b26d57bdf99237f04a810f254
(cherry picked from commit 226460f8)