RDMA/mlx4: Fix resource leak on error in mlx4_ib_create_srq()

RDMA/mlx4: Fix resource leak on error in mlx4_ib_create_srq()

Sashiko points out that mlx4_srq_alloc() was not undone during error
unwind, add the missing call to mlx4_srq_free().

Cc: stable@vger.kernel.org
Fixes: 225c7b1feef1 ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters")
Link: https://sashiko.dev/#/patchset/0-v1-e911b76a94d1%2B65d95-rdma_udata_rep_jgg%40nvidia.com?part=8
Link: https://patch.msgid.link/r/11-v1-41f3135e5565+9d2-rdma_ai_fixes1_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>