f-stack tools add root user check

[typochecker]

I am accustomed to using sudo instead of directly using the root user. When I forget to add the sudo prefix, the program only outputs an error message with a reason that is hard to guess.

aaa@aaaubuntu:~/speedtest$ /data/f-stack/tools/sbin/ifconfig
EAL: Cannot open '/run/user/1000/dpdk/rte/config' for rte_mem_config
EAL: FATAL: Cannot init config
EAL: Cannot init config
EAL: Error - exiting with code: 1
Cause: Error with EAL initialization