It actually means the delta block count of growfs. Rename it in order
to make it clear. Also introduce nb_div to avoid reusing `delta`.
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NGao Xiang <hsiangkao@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>