dm raid: clean up four equivalent goto tags in raid_ctr()

[ Upstream commit e74c874e ]

There are four equivalent goto tags in raid_ctr(), clean them up to
use just one.

There is no functional change and this is preparation to fix
raid_ctr()'s unprotected md_stop().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Stable-dep-of: 7d5fff89 ("dm raid: protect md_stop() with 'reconfig_mutex'")
Signed-off-by: Sasha Levin <sashal@kernel.org>