[PATCH] kthread: convert loop.c to kthread

Convert loop.c from the deprecated kernel_thread to kthread.  This patch
simplifies the code quite a bit and passes similar testing to the previous
submission on both emulated x86 and s390.

Changes since last submission:
	switched to using a rather simple loop based on
	wait_event_interruptible.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/loop.h b/include/linux/loop.h
index e76c761..191a595 100644
--- a/include/linux/loop.h
+++ b/include/linux/loop.h
@@ -59,10 +59,9 @@
 	struct bio 		*lo_bio;
 	struct bio		*lo_biotail;
 	int			lo_state;
-	struct completion	lo_done;
-	struct completion	lo_bh_done;
 	struct mutex		lo_ctl_mutex;
-	int			lo_pending;
+	struct task_struct	*lo_thread;
+	wait_queue_head_t	lo_event;
 
 	request_queue_t		*lo_queue;
 };