libsemanage/tests: include libsepol headers from $DESTDIR

When building and running tests on a system without SELinux with a
command similar to "make DESTDIR=/tmp/destdir install test", libsemanage
tests fail to build with the following error:

    In file included from utilities.h:20:0,
                     from utilities.c:24:
    ../src/handle.h:29:26: fatal error: sepol/handle.h: No such file or
    directory
     #include <sepol/handle.h>
                              ^

Fix this by adding the newly-installed directory under $DESTDIR (using
variable $PREFIX) in the search paths of the compiler.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
2 files changed