x86, msr: Use seek definitions instead of hard-coded values

Replace 0/1 by SEEK_SET/SEEK_CUR.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Link: http://lkml.kernel.org/r/1413576120-27147-1-git-send-email-fabf@skynet.be


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