SUNRPC: Replace clnt->cl_principal

The clnt->cl_principal is being used exclusively to store the service
target name for RPCSEC_GSS/krb5 callbacks. Replace it with something that
is stored only in the RPCSEC_GSS-specific code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1671e1f..09c7e3b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2717,10 +2717,13 @@
 static int nfs4_lookup_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
 				struct nfs_fsinfo *info, rpc_authflavor_t flavor)
 {
+	struct rpc_auth_create_args auth_args = {
+		.pseudoflavor = flavor,
+	};
 	struct rpc_auth *auth;
 	int ret;
 
-	auth = rpcauth_create(flavor, server->client);
+	auth = rpcauth_create(&auth_args, server->client);
 	if (IS_ERR(auth)) {
 		ret = -EACCES;
 		goto out;