ipmi: make alloc_recv_msg static

Make the needlessly global ipmi_alloc_recv_msg() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
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>