docs/scheduler/sched-design-CFS: formatting fix

Fix the rendering of the paragraph. Before the fix, the first line is
rendered in bold (I'm not quite sure why) and is also separated from the
rest of the paragraph, which is rendered with an indent.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210120001824.385168-3-kolyshkin@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/scheduler/sched-design-CFS.rst

@@ -34,9 +34,9 @@ In CFS the virtual runtime is expressed and tracked via the per-task
 p->se.vruntime (nanosec-unit) value.  This way, it's possible to accurately
 timestamp and measure the "expected CPU time" a task should have gotten.
 
-[ small detail: on "ideal" hardware, at any time all tasks would have the same
+   Small detail: on "ideal" hardware, at any time all tasks would have the same
    p->se.vruntime value --- i.e., tasks would execute simultaneously and no task
-  would ever get "out of balance" from the "ideal" share of CPU time.  ]
+   would ever get "out of balance" from the "ideal" share of CPU time.
 
 CFS's task picking logic is based on this p->se.vruntime value and it is thus
 very simple: it always tries to run the task with the smallest p->se.vruntime