ftpd: code chrink, fixed some minor bugs

ftpd: code chrink, fixed some minor bugs
ls: update comment
*: openlog fixes (added LOG_PID, set LOG_DAEMON as appropriate)

function                                             old     new   delta
xwrite_str                                             -      26     +26
cmdio_write_ok                                         -      15     +15
handle_cwd                                            40      45      +5
packed_usage                                       25668   25670      +2
cmdio_write_raw                                        7       9      +2
handle_upload_common                                 322     320      -2
udhcpd_main                                         1375    1372      -3
udhcpc_main                                         2362    2359      -3
port_cleanup                                          27      23      -4
handle_dir_common                                    221     209     -12
str_netfd_write                                       26       -     -26
cmdio_get_cmd_and_arg                                122       -    -122
ftpd_main                                           2208    2050    -158
------------------------------------------------------------------------------
   text    data     bss     dec     hex filename
 809933     476    7864  818273   c7c61 busybox_old
 809199     476    7864  817539   c7983 busybox_unstripped