statvfs/statvfs01.c: cleanup

* Delete some useless commtents.

* Some cleanup.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
statvfs/statvfs02.c: add new errno testes

* Add new errno testes for statvfs(2)
  - EFAULT
  - ELOOP
  - ENAMETOOLONG
  - ENOENT
  - ENOTDIR

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>