[PATCH] m68k: introduce task_thread_info

new helper - task_thread_info(task).  On platforms that have thread_info
allocated separately (i.e.  in default case) it simply returns
task->thread_info.  m68k wants (and for good reasons) to embed its thread_info
into task_struct.  So it will (in later patch) have task_thread_info() of its
own.  For now we just add a macro for generic case and convert existing
instances of its body in core kernel to uses of new macro.  Obviously safe -
all normal architectures get the same preprocessor output they used to get.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index 452a1d1..ee51568 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -859,7 +859,7 @@
 	if (group_dead && tsk->signal->leader)
 		disassociate_ctty(1);
 
-	module_put(tsk->thread_info->exec_domain->module);
+	module_put(task_thread_info(tsk)->exec_domain->module);
 	if (tsk->binfmt)
 		module_put(tsk->binfmt->module);