cxgb3 - Set the CQ_ERR bit in CQ contexts.

The cxgb3 driver is incorrectly configuring the HW CQ context for CQ's
that use overflow-avoidance.  Namely the RDMA control CQ.  This results
in a bad DMA from the device to bus address 0.  The solution is to set
the CQ_ERR bit in the context for these types of CQs.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>