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>
Approved by: re (gjb)

(cherry picked from commit 5842073a9b7471831e0da48d29dd984d575f4e9e)
(cherry picked from commit e298c1c3c257446eba06945a0b4755ca30387012)