FROMLIST: mm/damon/reclaim: Fix the timer always stays active

The timer stays active even if the reclaim mechanism is never enabled.
It is unnecessary overhead can be completely avoided by using module_param_cb() for enabled flag.

Signed-off-by: Hailong Tu <tuhailong@gmail.com>

Link: https://lore.kernel.org/all/20220421125910.1052459-1-tuhailong@gmail.com/



Bug: 228223814
Signed-off-by: Hailong Tu <tuhailong@oppo.com>
Change-Id: I77591e41ce424ce16a4a5c70e7a86cdae996a354