RDMA/qedr: Remove Unneeded variable rc

Fix the below warning reported by coccicheck:

drivers/infiniband/hw/qedr/verbs.c:2454:5-7: Unneeded variable: "rc".
Return "0" on line 2499

Link: https://lore.kernel.org/r/20190716173712.GA12949@hari-Inspiron-1545


Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Acked-by: Michal Kalderon <michal.kalderon@marvell.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>