builtin/show-ref: fix dead code when passing patterns

builtin/show-ref: fix dead code when passing patterns

When passing patterns to `git show-ref` we have some code that will
cause us to die if `verify && !quiet` is true. But because `verify`
indicates a different subcommand of git-show-ref(1) that causes us to
execute `cmd_show_ref__verify()` and not `cmd_show_ref__patterns()`, the
condition cannot ever be true.

Let's remove this dead code.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>