fabrics: permit bi-auth with secure concat TLS

Turns out it is not just uni-auth that is supported with secure
channel concat TLS but bi-auth as well. Earlier interpretation
of the NVMe spec on this topic was wrong as discussed recently
in the NVMe upstream mailing list at
https://lore.kernel.org/linux-nvme/[email protected]/T/#t.
So permit the same now in userspace.

Fixes: 5fdc131 ("fabrics: add error if dhchap-ctrl-secret is specified with --concat")

Signed-off-by: Martin George <[email protected]>

Author: martin-gpy

libnvme/src/nvme/fabrics.c

@@ -726,11 +726,6 @@ static int build_options(nvme_host_t h, nvme_ctrl_t c, char **argstr)
 		return -ENVME_CONNECT_INVAL;
 	}
 
-	if (cfg->concat && ctrlkey) {
-		nvme_msg(h->ctx, LOG_ERR, "cannot specify [--dhchap-ctrl-secret | -C] with --concat\n");
-		return -ENVME_CONNECT_INVAL;
-	}
-
 	if (cfg->tls) {
 		ret = __nvme_import_keys_from_config(h, c,
 			&keyring_id, &key_id);