Thanks to @NeQuissimus in a5c1985fef381b1fb5d75d3b4028ed5b5d4454b3 for
updating busybox, which since version 1.25 doesn't allow local variables
outside of functions anymore (which is the desired behaviour).
See the following upstream commit of busybox which is the change that
let's this problem surface:
https://git.busybox.net/busybox/commit/?id=ef2386b80abfb22ccb697ddbdd4047aacc395c50
So this has been an error I've made on my end in
67223ee205364afb203361b134f16b890c4d726c, because I originally had a
function for killing the processes but desired to inline it because it's
only used in one place.
This fixes the boot-stage1 NixOS test.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>