inetd: fix bug 1562 "inetd does not set argv[0] properly" (fix by IlyaPanfilov)

inetd: fix bug 1562 "inetd does not set argv[0] properly" (fix by IlyaPanfilov)
inetd: code shrink while at it

function                                             old     new   delta
static.SOCK_xxx                                        -       6      +6
getconfigent                                        1222    1123     -99
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 6/-99)             Total: -93 bytes
   text    data     bss     dec     hex filename
 776099     974    9420  786493   c003d busybox_old
 776020     974    9420  786414   bffee busybox_unstripped