sanitycheck: detect wrongly named tests and fail

Tests should always start with test_. If not, they will not be in the
report.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/scripts/sanity_chk/sanitylib.py b/scripts/sanity_chk/sanitylib.py
index f391d0d..b7ae76a 100644
--- a/scripts/sanity_chk/sanitylib.py
+++ b/scripts/sanity_chk/sanitylib.py
@@ -1406,6 +1406,9 @@
                 _matches = re.findall(
                     stc_regex,
                     main_c[suite_regex_match.end():suite_run_match.start()])
+                for match in _matches:
+                    if not match.decode().startswith("test_"):
+                        warnings = "Found a test that does not start with test_"
                 matches = [match.decode().replace("test_", "") for match in _matches]
                 return matches, warnings