lib: ensure subtests are not added to simple tests

Simple tests do not support subtests, so fail if igt_subtest is used in
one.

Signed-off-by: Thomas Wood <thomas.wood@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/igt_core.c b/lib/igt_core.c
index b937f43e..3fd45952 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -672,6 +672,7 @@ bool __igt_run_subtest(const char *subtest_name)
 {
 	assert(!in_subtest);
 	assert(!in_fixture);
+	assert(test_with_subtests);
 
 	if (list_subtests) {
 		printf("%s\n", subtest_name);