cpuset: trivial documentation fix s/N_MEMORY/N_HIGH_MEMORY/

Current implementation of cpuset track N_HIGH_MEMORY instead N_MEMORY.
(N_MEMORY doesn't exist in current implementation)
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/cpusets.txt

@@ -209,7 +209,7 @@ and name space for cpusets, with a minimum of additional kernel code.
 The cpus and mems files in the root (top_cpuset) cpuset are
 read-only.  The cpus file automatically tracks the value of
 cpu_online_map using a CPU hotplug notifier, and the mems file
-automatically tracks the value of node_states[N_MEMORY]--i.e.,
+automatically tracks the value of node_states[N_HIGH_MEMORY]--i.e.,
 nodes with memory--using the cpuset_track_online_nodes() hook.