The jfsIOWait() thread calls try_to_freeze() but lacks set_freezable(),
causing it to remain non-freezable by default. This prevents proper
freezing during system suspend.
Add set_freezable() to make the thread freezable as intended.
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>