net/smc: check port_idx of ib event

For robustness protect of higher port numbers than expected to avoid
setting bits behind our port_event_mask. In case of an DEVICE_FATAL
event all ports must be checked. The IB_EVENT_GID_CHANGE event is
provided in the global event handler, so handle it there. And handle a
QP_FATAL event instead of an DEVICE_FATAL event in the qp handler.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>