sched/fair: Fix nuisance kernel-doc warning

Work around kernel-doc warning ('*' in Sphinx doc means "emphasis"):

../kernel/sched/fair.c:7584: WARNING: Inline emphasis start-string without end-string.

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

kernel/sched/fair.c

···
  * number.
  *
  * Return: 1 when packing is required and a task should be moved to
- * this CPU.  The amount of the imbalance is returned in *imbalance.
+ * this CPU.  The amount of the imbalance is returned in env->imbalance.
  *
  * @env: The load balancing environment.
  * @sds: Statistics of the sched_domain which is to be packed