mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()

In damon_sysfs_kdamond_release(), we have use container_of() to get
"kdamond" pointer, so there no need to get it once again.

Link: https://lkml.kernel.org/r/20220303075314.22502-1-xhao@linux.alibaba.comSigned-off-by: NXin Hao <xhao@linux.alibaba.com>
Reviewed-by: NSeongJae Park <sj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/damon/sysfs.c

@@ -2345,7 +2345,7 @@ static void damon_sysfs_kdamond_release(struct kobject *kobj)
 
 	if (kdamond->damon_ctx)
 		damon_destroy_ctx(kdamond->damon_ctx);
-	kfree(container_of(kobj, struct damon_sysfs_kdamond, kobj));
+	kfree(kdamond);
 }
 
 static struct kobj_attribute damon_sysfs_kdamond_state_attr =