tracing: fix the return value of trace selftest

This patch is to fix the return value of trace_selftest_startup_sysprof
and trace_selftest_startup_branch on failure.
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

kernel/trace/trace_selftest.c

@@ -622,7 +622,7 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
 	ret = tracer_init(trace, tr);
 	if (ret) {
 		warn_failed_init_tracer(trace, ret);
-		return 0;
+		return ret;
 	}
 
 	/* Sleep for a 1/10 of a second */
@@ -634,6 +634,11 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
 	trace->reset(tr);
 	tracing_start();
 
+	if (!ret && !count) {
+		printk(KERN_CONT ".. no entries found ..");
+		ret = -1;
+	}
+
 	return ret;
 }
 #endif /* CONFIG_SYSPROF_TRACER */
@@ -661,6 +666,11 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
 	trace->reset(tr);
 	tracing_start();
 
+	if (!ret && !count) {
+		printk(KERN_CONT ".. no entries found ..");
+		ret = -1;
+	}
+
 	return ret;
 }
 #endif /* CONFIG_BRANCH_TRACER */