selftests: Fix memfd test run-time regression

Commit d3fd949a ("selftests: Fix memfd to support relocatable
build (O=objdir)") introduced regression run-time regression with
a change to include programs that should be run from shell scripts
to list of programs that run as independent tests. This fix restores
the original designation.

Fixes: d3fd949a ("selftests: Fix memfd to support relocatable build (O=objdir)")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>