qlcnic: Fix missing error codes

In the original code, the error codes returned from some of the functions
are not caught and sent up the caller chain. Fixed it here.

Signed-off-by: Sony Chacko <sony.chacko@qlogic.com>
Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>