qlcnic: Stop pause ctrl frames on fw hang.

When firmware hang is detected, fw should stop sending pause control frames.

Signed-off-by: Sritej Velaga <sritej.velaga@qlogic.com>
Signed-off-by: Sony Chacko <sony.chacko@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>