[check-licenses] Update pipeline error syntax order

Update the compliance failure messages in validate.go and report.go to
output the exact policy add and allowlist add commands using the new
correct nested subcommand syntax order (flags before positional args).
This allows developers to copy-paste the commands directly from the
logs.

Change-Id: I1a48916fe7ea1ba869de09adf7bf12c427bd332f
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1602051
Commit-Queue: Jerry Belton <jcecil@google.com>
Reviewed-by: Jiaming Li <lijiaming@google.com>