deal with resource allocation bugs in arcmsr

a) for type B we should _not_ iounmap() acb->pmu; it's not ioremapped.
b) for type B we should iounmap() two regions we _do_ ioremap.
c) if ioremap() fails, we need to bail out (and clean up).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>