west: sign.py: recommend separator -- tool_args always

In the following command, the first argument `for_rimage` is passed to
`rimage` whereas `--for west` goes to west.

```
west sign  for_rimage --for west
```

This is somehow valid but we really don't want anyone to do that.

Signed-off-by: Marc Herbert <marc.herbert@intel.com>
This commit is contained in:
Marc Herbert 2023-12-11 00:56:08 +00:00 committed by Carles Cufí
commit c13cf99f2a

View file

@ -34,9 +34,11 @@ In the simplest usage, run this from your build directory:
west sign -t your_tool -- ARGS_FOR_YOUR_TOOL
The "ARGS_FOR_YOUR_TOOL" value can be any additional
arguments you want to pass to the tool, such as the location of a
signing key etc.
The "ARGS_FOR_YOUR_TOOL" value can be any additional arguments you want to
pass to the tool, such as the location of a signing key etc. Depending on
which sort of ARGS_FOR_YOUR_TOOLS you use, the `--` separator/sentinel may
not always be required. To avoid ambiguity and having to find and
understand POSIX 12.2 Guideline 10, always use `--`.
See tool-specific help below for details.'''