cxgb3: Leave interrupts for fatal errors asserted in common code.

Platform code needs to deal with them now.

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