x86, mce: Improve timeout error messages

There are four different possible types of timeouts.  Distinguish
them in the logs to help debug them.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/0fa6d2653a54a01c48b43a3583caf950ea99606e.1419178397.git.luto@amacapital.net


Signed-off-by: Borislav Petkov <bp@suse.de>