nvme-rdma: fix error code in nvme_rdma_setup_ctrl

nvme-rdma: fix error code in nvme_rdma_setup_ctrl

BugLink: https://bugs.launchpad.net/bugs/1951822
[ Upstream commit 09748122009aed7bfaa7acc33c10c083a4758322 ]

In case that icdoff is not zero or mandatory keyed sgls are not
supported by the NVMe/RDMA target, we'll go to error flow but we'll
return 0 to the caller. Fix it by returning an appropriate error code.

Fixes: c66e2998c8ca ("nvme-rdma: centralize controller setup sequence")
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>