arcmsr(4): Fixed no action of hot plugging device on type_F adapter.
Many thanks to Areca for continuing to support FreeBSD.
Submitted by: 黃清隆 <ching2048 areca com tw>
MFC after: 3 days
(cherry picked from commit 5842073a9b7471831e0da48d29dd984d575f4e9e)