Gofmt should not check vendor files

[Jiaxin Shan]

Notice current verify scripts verify vendors files and it's blocking code checking in.

kubebench/hack/verify-gofmt.sh

Line 3 in 37ffc2f

 if [ -n "$(gofmt -s -l .)" ]; then 

[Jiaxin Shan]

PR got merged. I will close this issue