Add functions.sh to TEST_PROGS_EXTENDED so that it is installed along
with the rest of the selftests and they can be run.
Originally-by: Shuah Khan <shuah@kernel.org> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Petr Mladek <pmladek@suse.com>