ipmi: style fixes in the base code

Lots of style fixes for the base IPMI driver.  No functional changes.
Basically fixes everything reported by checkpatch and fixes the comment
style.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>