flow_offload: use flow_indr_block_cb_alloc/remove function

Prepare fix the bug in the next patch. use flow_indr_block_cb_alloc/remove
function and remove the __flow_block_indr_binding.

Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>