Fix use command

[hakamata-rui]

ls command output vary from OS to OS.
In my case, awk '{print $9}' shows time of last modification.
Since the last field always shows directory name, we have to get it by $NF to get dir names of go versions.

$ ls -l
total 0
drwxr-xr-x  20 abc123  Hoge Users  680  3 29 15:23 1.8