sched/fair: Remove unneeded prototype of capacity_of()

The prototype of that function was already hoisted up in:

  commit 3b1baa64

 ("sched/fair: Add 'group_misfit_task' load-balance type")

but that seems to have been missed. Get rid of the extra prototype.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Quentin Perret <quentin.perret@arm.com>
Cc: Dietmar.Eggemann@arm.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: morten.rasmussen@arm.com
Fixes: 2802bf3c ("sched/fair: Add over-utilization/tipping point indicator")
Link: http://lkml.kernel.org/r/20190416140621.19884-1-valentin.schneider@arm.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>