qed: Set HW-channel to ready before ACKing VF

When PF responds to the VF requests it also cleans the HW-channel
indication in firmware to allow further VF messages to arrive,
but the order currently applied is wrong -
The PF is copying by DMAE the response the VF is polling on for
completion, and only afterwards sets the HW-channel to ready state.

This creates a race condition where the VF would be able to send
an additional message to the PF before the channel would get ready
again, causing the firmware to consider the VF as malicious.

Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>