[PATCH] fixup: mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}

[Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>]

Dan Carpenter reported the following bug:

```
The patch b6884b5f15cf: "mm: shrinker: add a secondary array for
shrinker_info::{map, nr_deferred}" from Sep 11, 2023 (linux-next),
leads to the following Smatch static checker warning:

	mm/shrinker.c:100 alloc_shrinker_info()
	warn: inconsistent returns '&shrinker_mutex'.
```

To fix it, unlock the &shrinker_rwsem before the call to
free_shrinker_info().

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/linux-mm/f960ae49-078c-4c00-9516-da31fc1a17d6@moroto.mountain/
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
 mm/shrinker.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/shrinker.c b/mm/shrinker.c
index 893079806553..e9644cda80b5 100644
--- a/mm/shrinker.c
+++ b/mm/shrinker.c
@@ -95,6 +95,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg)
 	return ret;
 
 err:
+	up_write(&shrinker_rwsem);
 	free_shrinker_info(memcg);
 	return -ENOMEM;
 }
-- 
2.30.2