Hoist the inode cluster checks out of the inobt record check loop into
a separate function in preparation for refactoring of that loop.  No
functional changes here; that's in the next patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>