hook tests: fix redirection logic error in 96e7225b310

hook tests: fix redirection logic error in 96e7225b310

The tests added in 96e7225b310 (hook: add 'run' subcommand,
2021-12-22) were redirecting to "actual" both in the body of the hook
itself and in the testing code below.

The net result was that the "2>>actual" redirection later in the test
wasn't doing anything. Let's have those redirection do what it looks
like they're doing.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>