[PATCH] [TRIVIAL] kasan: Add a prototype of task_struct to avoid warning

[Masami Hiramatsu <mhiramat@kernel.org>]

Add a prototype of task_struct to fix below warning on arm64.

  CC      arch/arm64/kernel/probes/kprobes.o
In file included from /tmp/linux/arch/arm64/kernel/probes/kprobes.c:19:0:
/tmp/linux/include/linux/kasan.h:81:53: warning: 'struct task_struct' declared inside parameter list will not be visible outside of this definition or declaration
 static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
                                                     ^~~~~~~~~~~
As same as other types (kmem_cache, page, and vm_struct)
this adds a prototype of task_struct data structure on
top of kasan.h.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
---
 include/linux/kasan.h |    1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 820c0ad..c9df9e1 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -7,6 +7,7 @@
 struct kmem_cache;
 struct page;
 struct vm_struct;
+struct task_struct;
 
 #ifdef CONFIG_KASAN