[PATCH] ipmi: fix watchdog so the device can be reopened on an unexpected close

If there is an unexpected close, still allow the watchdog interface to be
re-opened on the IPMI watchdog.

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>