Merge branch 'nd/dir-exclude-cleanup' into maint

The "exclude_list" structure has the usual "alloc, nr" pair of fields to be used by ALLOC_GROW(), but clear_exclude_list() forgot to reset 'alloc' to 0 when it cleared 'nr' to discard the managed array. * nd/dir-exclude-cleanup: dir.c: clean the entire struct in clear_exclude_list()