A build toolchain may override CPPFLAGS on the command line of "make".
Doing so currently breaks libsepol/tests compilation, as it requires
"-I../include/ -I$(CHECKPOLICY)" to be provided in gcc's arguments.
This completes commit 15f2740733 ("Makefiles: override *FLAGS and
*LIBS").
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
when building packages (e.g. for openSUSE Linux)
(random) filesystem order of input files
influences ordering of functions in the output,
thus without the patch, builds (in disposable VMs) would usually differ.
See https://reproducible-builds.org/ for why this matters.
