udhcp: get rid of bb_info_msg()

udhcp: get rid of bb_info_msg()

function                                             old     new   delta
udhcpd_main                                         1501    1531     +30
d6_recv_raw_packet                                   251     264     +13
perform_d6_release                                   188     198     +10
udhcpc6_main                                        2443    2449      +6
udhcp_recv_raw_packet                                582     588      +6
udhcp_recv_kernel_packet                             132     138      +6
send_d6_renew                                        140     146      +6
d6_recv_kernel_packet                                118     124      +6
send_renew                                            77      82      +5
send_discover                                         85      90      +5
send_decline                                          84      89      +5
send_d6_select                                        97     102      +5
send_d6_discover                                     174     179      +5
perform_release                                      167     172      +5
count_lines                                           72      74      +2
udhcpc_main                                         2836    2837      +1
bb_info_msg                                          125       -    -125
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 17/4 up/down: 117/-180)         Total: -63 bytes
   text	   data	    bss	    dec	    hex	filename
 924935	    906	  17160	 943001	  e6399	busybox_old
 924736	    906	  17160	 942802	  e62d2	busybox_unstripped

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