This way, we can zero them all in one go.
We do malloc() anyway, thus nothing is lost by mallocing "globals"
function old new delta
arping_main 1683 1686 +3
finish 100 86 -14
catcher 350 310 -40
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(add/remove: 0/0 grow/shrink: 1/2 up/down: 3/-54) Total: -51 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>