RDMA/srpt: Fix error return code in srpt_cm_req_recv()

RDMA/srpt: Fix error return code in srpt_cm_req_recv()

Fix to return a negative error code from the error handling case instead
of 0, as done elsewhere in this function.

Fixes: db7683d7deb2 ("IB/srpt: Fix login-related race conditions")
Link: https://lore.kernel.org/r/20210408113132.87250-1-wangwensheng4@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>