frv: Use correct size for task_struct allocation

alloc_task_struct_node() allocates THREAD_SIZE and maintains some
weird refcount in the allocated memory. This never blew up as
task_struct size on 32bit machines was always less than THREAD_SIZE

Allocate just sizeof(struct task_struct) and get rid of the magic
refcounting.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120503085033.898475542@linutronix.de

arch/frv/kernel/process.c

@@ -45,17 +45,12 @@ EXPORT_SYMBOL(pm_power_off);
 
 struct task_struct *alloc_task_struct_node(int node)
 {
-	struct task_struct *p = kmalloc_node(THREAD_SIZE, GFP_KERNEL, node);
-
-	if (p)
-		atomic_set((atomic_t *)(p+1), 1);
-	return p;
+	return kmalloc_node(sizeof(task_struct), GFP_KERNEL, node);
 }
 
 void free_task_struct(struct task_struct *p)
 {
-	if (atomic_dec_and_test((atomic_t *)(p+1)))
-		kfree(p);
+	kfree(p);
 }
 
 static void core_sleep_idle(void)