s390/test_unwind: print test suite start/end info

Add couple of additional info lines to make it easier to match
test suite output and results.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/lib/test_unwind.c

@@ -311,6 +311,7 @@ do {									\
 	}								\
 } while (0)
 
+	pr_info("running stack unwinder tests");
 	TEST(UWM_DEFAULT);
 	TEST(UWM_SP);
 	TEST(UWM_REGS);
@@ -337,8 +338,13 @@ do {									\
 	TEST(UWM_PGM | UWM_SP | UWM_REGS);
 #endif
 #undef TEST
+	if (failed) {
+		pr_err("%d of %d stack unwinder tests failed", failed, total);
+		WARN(1, "%d of %d stack unwinder tests failed", failed, total);
+	} else {
+		pr_info("all %d stack unwinder tests passed", total);
+	}
 
-	WARN(failed, "%d of %d unwinder tests failed", failed, total);
 	return failed ? -EINVAL : 0;
 }