sched: Rename sched.c as sched/core.c in comments and Documentation

Most of the stuff from kernel/sched.c was moved to kernel/sched/core.c long time
back and the comments/Documentation never got updated.

I figured it out when I was going through sched-domains.txt and so thought of
fixing it globally.

I haven't crossed check if the stuff that is referenced in sched/core.c by all
these files is still present and hasn't changed as that wasn't the motive behind
this patch.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/cdff76a265326ab8d71922a1db5be599f20aad45.1370329560.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f463a46..5ec99e5 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -803,7 +803,7 @@
 #define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x))
 
 /*
- * This has to have a higher priority than migration_notifier in sched.c.
+ * This has to have a higher priority than migration_notifier in sched/core.c.
  */
 #define perf_cpu_notifier(fn)						\
 do {									\