RDMA/qedr: remove set but not used variable 'ib_ctx'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/infiniband/hw/qedr/verbs.c: In function 'qedr_create_srq':
drivers/infiniband/hw/qedr/verbs.c:1436:22: warning:
 variable 'ib_ctx' set but not used [-Wunused-but-set-variable]

drivers/infiniband/hw/qedr/verbs.c: In function 'qedr_create_user_qp':
drivers/infiniband/hw/qedr/verbs.c:1701:22: warning:
 variable 'ib_ctx' set but not used [-Wunused-but-set-variable]

Fixes: b0ea0fa5 ("IB/{core,hw}: Have ib_umem_get extract the ib_ucontext from ib_udata")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>