The journald test was failing as sysroot was not being passed to the
compiler in the compile test. This is due to the fact we were explicitly
defining sysroot in the CXXFLAGS and not in CFLAGS.

Change-Id: I4b4bda71f9aabc8e420e0e89ff3cc8fa3bbca201
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>