[dts] [PATCH V2] fix update_system case failed

[Liu, Yong]

Thanks, huilong. Applied.

On 10/12/2017 02:24 PM, xu,huilong wrote:
>      some times, when use data cmdline get dut systerm time, after kill ptpclent example.
>      the output will include "[1]+  Terminated              ./examples/ptpclient/build/ptpclient -c f -n 3 -- -T 1 -p 0x1"
>      so should get systerm time again.
>
> Signed-off-by: xu,huilong<huilongx.xu at intel.com>