runner and all_tests should exit with failure on failing tests.

Otherwise the bots don't notice.

BUG=473924

Change-Id: Idb8cc4c255723ebbe2d52478040a70648910bf37
Reviewed-on: https://boringssl-review.googlesource.com/4232
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/runner.go b/ssl/test/runner/runner.go
index f14833b..084ae46 100644
--- a/ssl/test/runner/runner.go
+++ b/ssl/test/runner/runner.go
@@ -3404,4 +3404,8 @@
 			fmt.Fprintf(os.Stderr, "Error: %s\n", err)
 		}
 	}
+
+	if !testOutput.allPassed {
+		os.Exit(1)
+	}
 }