tenders, FreeBSD, tap: Ignore "up" variable to avoid compiler warning
tenders, FreeBSD, tap: Ignore "up" variable to avoid compiler warning

The unused-but-set-variable warning was emitted for the variable "up", which is
not used on FreeBSD. To keep the code simple (not introducing further ifdefs),
just ignore it via an empty conditional. Fixes #519.

Solo5/solo5,Solo5/solo5