s3:libsmb/unexpected: pass nmbd_socket_dir from the callers of nb_packet_{server_crea...

s3:libsmb/unexpected: pass nmbd_socket_dir from the callers of nb_packet_{server_create,reader_send}()

This will allow source4/nbt_server to make use of
nb_packet_server_create().

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15620

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(cherry picked from commit 696505a1efbcc9803a287d8c267fed9d04bf8885)