x86, msr: Convert printk to pr_foo()

Also define pr_fmt.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Link: http://lkml.kernel.org/r/1413576110-27103-1-git-send-email-fabf@skynet.be


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>