symlinks: do not include startup_info->original_cwd in dir removal

symlinks: do not include startup_info->original_cwd in dir removal

symlinks has a pair of schedule_dir_for_removal() and
remove_scheduled_dirs() functions that ensure that directories made
empty by removing other files also themselves get removed.  However, we
want to exclude startup_info->original_cwd and leave it around.  This
avoids the user getting confused by subsequent git commands (and non-git
commands) that would otherwise report confusing messages about being
unable to read the current working directory.

Acked-by: Derrick Stolee <stolee@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>