LU-6415 utils: deny non-root user for changelog operations

LU-6415 utils: deny non-root user for changelog operations

To avoid potential security problems, non-privileged users should
have no permission to run 'lfs changelog' & 'lfs changelog_clear'.

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I5f38ba5b139f2f3b6495d3c97d82a47daecf8187
Reviewed-on: http://review.whamcloud.com/14280
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>