systemd: Replace use of %m in printf formats

The patch is applied optionally only to uclibc builds
Also move the mkostemp replacement patch to uclibc only list

Not perfect yet but gets us going on uclibc

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>