Documentation/admin-guide: cgroup-v1/rdma: drop doubled word

Drop the doubled word "echo".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: cgroups@vger.kernel.org
Link: https://lore.kernel.org/r/20200704032020.21923-3-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/cgroup-v1/rdma.rst

@@ -114,4 +114,4 @@ Following resources can be accounted by rdma controller.
 
 (d) Delete resource limit::
 
-	echo echo mlx4_0 hca_handle=max hca_object=max > /sys/fs/cgroup/rdma/1/rdma.max
+	echo mlx4_0 hca_handle=max hca_object=max > /sys/fs/cgroup/rdma/1/rdma.max