iommu/vt-d: Improve fault handler error messages

Remove new line in error logs, avoid duplicate and explicit pr_fmt.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fixes: 0ac2491f ('x86, dmar: move page fault handling code to dmar.c')
Signed-off-by: Joerg Roedel <jroedel@suse.de>