um: switch close_chan() to struct line

... and switch chan_interrupt() to directly calling close_one_chan(),
so we can lose delay_free_irq argument of close_chan() as well.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/drivers/chan.h b/arch/um/drivers/chan.h
index d3974a9..02b5a76 100644
--- a/arch/um/drivers/chan.h
+++ b/arch/um/drivers/chan.h
@@ -40,7 +40,7 @@
 extern void reactivate_chan(struct chan *chan, int irq);
 extern void chan_enable_winch(struct chan *chan, struct tty_struct *tty);
 extern int enable_chan(struct line *line);
-extern void close_chan(struct list_head *chans, int delay_free_irq);
+extern void close_chan(struct line *line);
 extern int chan_window_size(struct line *line, 
 			     unsigned short *rows_out, 
 			     unsigned short *cols_out);