If we select a host build, we'll have the same assert from
ppsi::arch-unix, becauseI added a non-libc assert to ppsi while adding
it to wrpc-sw.  But ppsi doesn't build its own asser for arch-wrpc, so
the only proble is with host builds.

(thanks randconfig)
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>