Small patches for pkg_add

[Baptiste Daroussin]

> Great!
>
> This looks good, but I have a few suggestions:
>
> You should be a little more careful about error handling.
> In particular, after any failure, archive_error_string(a)
> will hold an error message that you probably want to
> print out for the user's benefit.
>
> In particular, you should print the error message
> after a failure of archive_read_open_filename(),
> archive_read_extract(), or archive_read_next_header().
>
> You can also simplify slightly by omitting calls to
> archive_read_data_skip() (it's never needed).
>
> Tim
>

Thanks, I'll do that
FYI I opened a git for that work : http://git.etoilebsd.net/cgit/pkg_install/
I'll add what you advice me todo

regards,
Bapt