reiserfs: use more consistent printk formatting

The output format between a warning/error/panic/info/etc changes with
which one is used.

The following patch makes the messages more internally consistent, but also
more consistent with other Linux filesystems.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>