sched/rt: Use resched_curr() in task_tick_rt()

Some time ago PREEMPT_NEED_RESCHED was implemented,
so reschedule technics is a little more difficult now.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140922183642.11015.66039.stgit@localhost


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