sh: Use SLAB_PANIC for thread_info slab cache.

Presently this has a BUG_ON() for failure cases, as powerpc does. Switch
this over to a SLAB_PANIC instead.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/process.c

@@ -26,8 +26,7 @@ void free_thread_info(struct thread_info *ti)
 void thread_info_cache_init(void)
 {
 	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
-					      THREAD_SIZE, 0, NULL);
-	BUG_ON(thread_info_cache == NULL);
+					      THREAD_SIZE, SLAB_PANIC, NULL);
 }
 #else
 struct thread_info *alloc_thread_info(struct task_struct *tsk)