xfs: use named array initializers for log item dumping

Use named array initializers for the string arrays used to dump log
items, rather than depending on the order being maintained correctly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>