cxgb4vf: Fix bug where we were only allocating one queue in MSI mode

Fix bug in setup_sge_queues() where we were incorrectly only allocating a
single "Queue Set" for MSI mode.

Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>