Fix sudo cat Permission denied error
Fix sudo cat Permission denied error

Last commit [0], using sudo cat, this will gievs the error:
/etc/systemd/system/docker.service.d/docker.conf: Permission denied

This patch will fix this.

[0]: I2154919c394e546edac56934c8860d4177fc9603

Change-Id: I87a8b7397d2dad2d26eac9a020d5ea3b21645aa2

kevin-zhaoshuai/zun,kevin-zhaoshuai/zun,kevin-zhaoshuai/zun