busybox

setpriv: dump ambient capabilities

As with the previous commit, this commit introduces the ability to dump
the set of ambient capabilities.

function                                             old     new   delta
setpriv_main                                         982    1129    +147
.rodata                                           146148  146198     +50

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>