qed: iWARP - fix uninitialized callback

Fix uninitialized variable warning by static checker.

Fixes: ae3488ff

 ("qed: Add ll2 connection for processing unaligned MPA packets")
Signed-off-by: Ariel Elior <ariel.elior@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>