x86: Use common threadinfo allocator

The only difference is the free_thread_info function, which frees
xstate.

Use the new arch_release_task_struct() function instead and switch
over to the core allocator.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120505150141.559556763@linutronix.de
Cc: x86@kernel.org
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 8215458..e817315 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -76,10 +76,9 @@
 	fpu_free(&tsk->thread.fpu);
 }
 
-void free_thread_info(struct thread_info *ti)
+void arch_release_task_struct(struct task_struct *tsk)
 {
-	free_thread_xstate(ti->task);
-	free_pages((unsigned long)ti, THREAD_ORDER);
+	free_thread_xstate(tsk);
 }
 
 void arch_task_cache_init(void)