Description: md: Don't register sync_thread for reshape directly
References:
Notes:
 carnil> Introduced in f67055780caa ("[PATCH] md: Checkpoint and allow restart of raid5
 carnil> reshape")
 carnil> f52f5c71f3d4 ("md: fix stopping sync thread"). Vulnerable versions: 2.6.17-rc1
 carnil> 6.7-rc5.
Bugs:
upstream: released (6.8-rc6) [ad39c08186f8a0f221337985036ba86731d6aafe]
6.7-upstream-stable: released (6.7.7) [13b520fb62b772e408f9b79c5fe18ad414e90417]
6.6-upstream-stable: needed
6.1-upstream-stable: needed
5.10-upstream-stable: needed
4.19-upstream-stable: needed
sid: released (6.7.7-1)
6.1-bookworm-security: needed
5.10-bullseye-security: needed
4.19-buster-security: needed