sanitycheck: exit thread executor on exceptions

When something goes wrong, exit thread execution pool and report and
error.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/scripts/sanitycheck b/scripts/sanitycheck
index 4b41ae6..73b87f7 100755
--- a/scripts/sanitycheck
+++ b/scripts/sanitycheck
@@ -2760,7 +2760,8 @@
                     try:
                         data = future.result()
                     except Exception as exc:
-                        print('%r generated an exception: %s' % (test, exc))
+                        sys.exit('%r generated an exception: %s' % (test, exc))
+
                     else:
                         if data:
                             verbose(data)