mm/damon/lru_sort: reset enabled when DAMON start failed

JIRA: https://issues.redhat.com/browse/RHEL-104908

This patch is a backport of the following upstream commit:
commit b91b82e
Author: SeongJae Park <sj@kernel.org>
Date:   Sun Jul 6 12:32:06 2025 -0700

    mm/damon/lru_sort: reset enabled when DAMON start failed

    When the startup fails, 'enabled' parameter is not reset.  As a result,
    users show the parameter 'Y' while it is not really working.  Fix it by
    resetting 'enabled' to 'false' when the work is failed.

    Link: https://lkml.kernel.org/r/20250706193207.39810-6-sj@kernel.org
    Fixes: 7a034fb ("mm/damon/lru_sort: enable and disable synchronously")
    Signed-off-by: SeongJae Park <sj@kernel.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Audra Mitchell <audra@redhat.com>

Author: Audra Mitchell

mm/damon/lru_sort.c

@@ -335,7 +335,7 @@ static int __init damon_lru_sort_init(void)
 	int err = damon_modules_new_paddr_ctx_target(&ctx, &target);
 
 	if (err)
-		return err;
+		goto out;
 
 	ctx->callback.after_wmarks_check = damon_lru_sort_after_wmarks_check;
 	ctx->callback.after_aggregation = damon_lru_sort_after_aggregation;
@@ -344,6 +344,9 @@ static int __init damon_lru_sort_init(void)
 	if (enabled)
 		err = damon_lru_sort_turn(true);
 
+out:
+	if (err && enabled)
+		enabled = false;
 	return err;
 }