mm/damon/lru_sort: fix potential memory leak in damon_lru_sort_init()

'damon_lru_sort_init()' returns an error when 'damon_select_ops()' fails without freeing 'ctx' which allocated before. This commit fixes the potential memory leak by freeing 'ctx' under the situation.

Commit 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting"), which caused the problem is not in the mainline but mm-stable. Please meld this into the commit.

---
 mm/damon/lru_sort.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

index c276736a071c..9de6f00a71c5 100644
@@ -524,8 +524,10 @@ static int __init damon_lru_sort_init(void)
 	if (!ctx)
 		return -ENOMEM;
 
-	if (damon_select_ops(ctx, DAMON_OPS_PADDR))
+	if (damon_select_ops(ctx, DAMON_OPS_PADDR)) {
+		damon_destroy_ctx(ctx);
 		return -EINVAL;
+	}
 
 	ctx->callback.after_wmarks_check = damon_lru_sort_after_wmarks_check;
 	ctx->callback.after_aggregation = damon_lru_sort_after_aggregation;

2.25.1