sched/fair: Fix documentation file path

The 'tip' prefix probably referred to the -tip tree and is not required,
remove it.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180515165328.24899-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

init/Kconfig

@@ -738,7 +738,7 @@ config CFS_BANDWIDTH
 	  tasks running within the fair group scheduler.  Groups with no limit
 	  set are considered to be unconstrained and will run with no
 	  restriction.
-	  See tip/Documentation/scheduler/sched-bwc.txt for more information.
+	  See Documentation/scheduler/sched-bwc.txt for more information.
 
 config RT_GROUP_SCHED
 	bool "Group scheduling for SCHED_RR/FIFO"