dm flakey: return -EINVAL on interval bounds error in flakey_ctr()

Fix to return error code -EINVAL instead of 0, as is done elsewhere in
this function.

Fixes: e80d1c805a ("dm: do not override error code returned from dm_get_device()")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-flakey.c

@@ -200,11 +200,13 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	if (!(fc->up_interval + fc->down_interval)) {
 		ti->error = "Total (up + down) interval is zero";
+		r = -EINVAL;
 		goto bad;
 	}
 
 	if (fc->up_interval + fc->down_interval < fc->up_interval) {
 		ti->error = "Interval overflow";
+		r = -EINVAL;
 		goto bad;
 	}