SUNRPC: Fix a credential refcount leak

All callers of __rpc_clone_client() pass in a value for args->cred,
meaning that the credential gets assigned and referenced in
the call to rpc_new_client().

Reported-by: Ido Schimmel <idosch@idosch.org>
Fixes: 79caa5f ("SUNRPC: Cache cred of process creating the rpc_client")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/clnt.c

@@ -634,7 +634,6 @@ static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 	new->cl_discrtry = clnt->cl_discrtry;
 	new->cl_chatty = clnt->cl_chatty;
 	new->cl_principal = clnt->cl_principal;
-	new->cl_cred = get_cred(clnt->cl_cred);
 	return new;
 
 out_err: