xfs_scrub: reclassify runtime errors

xfs_scrub: reclassify runtime errors

If the program encounters runtime errors, these should be noted as
information.  Because these errors abort the execution flow (which is
counted as a runtime error), we need only call str_info to log the
event.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>