Bug 29469: (bug 17600 follow-up) Fix tag approval/rejection from staff

Bug 29469: (bug 17600 follow-up) Fix tag approval/rejection from staff

Usage: POSIX::exit(status) at /kohadevbox/koha/tags/review.pl line 72.                                                                                                                                                at /usr/share/perl/5.28/Carp.pm line 289
        Carp::croak('Usage: POSIX::exit(status)') called at /usr/lib/x86_64-linux-gnu/perl/5.28/POSIX.pm line 22
        POSIX::usage('exit(status)') called at (eval 2066) line 3

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>