qed: Fix null-pointer dereference in qed_rdma_create_qp()

Fix a possible null-pointer dereference in qed_rdma_create_qp().

Changes from V2:
- Revert checkpatch fixes.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Shai Malin <smalin@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>