libbb: introduce and use bb_getsockname()

function                                             old     new   delta
bb_getsockname                                         -      18     +18
xrtnl_open                                            88      83      -5
do_iplink                                           1216    1209      -7
arping_main                                         1686    1668     -18
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(add/remove: 2/0 grow/shrink: 0/3 up/down: 18/-30)            Total: -12 bytes

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