xfs_repair: fix broken EFSBADCRC/EFSCORRUPTED usage with buffer errors

xfs_repair: fix broken EFSBADCRC/EFSCORRUPTED usage with buffer errors

When we encounter CRC or verifier errors, bp->b_error is set to
-EFSBADCRC and -EFSCORRUPTED; note the negative sign.  For whatever
reason, repair and db use the positive versions, and therefore fail to
notice the error, so fix all the broken uses.

Note however that the db and repair turn the negative codes returned
by libxfs into positive codes that can be used with strerror.

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