tcpudp: shrink per-host rate-limiting code

tcpudp: shrink per-host rate-limiting code

function                                             old     new   delta
tcpudpsvd_main                                      1775    1780      +5
ipsvd_perhost_add                                    108     107      -1
cclen                                                  4       -      -4
cc                                                     4       -      -4
ipsvd_perhost_init                                    30      25      -5
ipsvd_perhost_remove                                  80      44     -36
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 1/3 up/down: 5/-50)             Total: -45 bytes
   text	   data	    bss	    dec	    hex	filename
 933358	    473	   6852	 940683	  e5a8b	busybox_old
 933326	    473	   6844	 940643	  e5a63	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>