systemd: Upgrade to 198

Tested on ppc and x86_64
compile tested for uclibc

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
qemuimage-testlib: Capture stderror in the logs as well as stdout

This allows error messages to be captured in the logs which is helpful.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>