In velocity_give_rx_desc(), there should be a wmb() between resetting the
first four bytes of rdesc0 and setting owner. As resetting the first four
bytes isn't necessary, I just removed the function and directly set owner.
Another rationale for removing the function:
The function doesn't handle synchronization. We should do wmb() before
calling the function.  So, I think using bare assignment makes the fact
more explicit.
Signed-off-by: Tejun Heo <tj@home-tj.org>