selftests: actually run the various net selftests

These self tests are just self contained binaries, they are not run by
any of the scripts in the directory.  This means they need to be marked
with TEST_GEN_PROGS to actually be run, not TEST_GEN_FILES.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>