sched/preempt/x86: Fix voluntary preempt for x86

The #ifdef CONFIG_PREEMPT is both not needed and wrong.

Its not required because asm/preempt.h should provide
{set,clear}_preempt_need_resched() regardless and its wrong because
for voluntary preempt we still rely on PREEMPT_NEED_RESCHED.

Reported-and-Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Fixes: 8cb75e0c4ec9 ("sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding")
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20140122102435.GH31570@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/preempt.h

@@ -134,7 +134,6 @@ do { \
 #undef preempt_check_resched
 #endif
 
-#ifdef CONFIG_PREEMPT
 #define preempt_set_need_resched() \
 do { \
 	set_preempt_need_resched(); \
@@ -144,10 +143,6 @@ do { \
 	if (tif_need_resched()) \
 		set_preempt_need_resched(); \
 } while (0)
-#else
-#define preempt_set_need_resched() do { } while (0)
-#define preempt_fold_need_resched() do { } while (0)
-#endif
 
 #ifdef CONFIG_PREEMPT_NOTIFIERS