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.com


Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>