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/line.c b/arch/um/drivers/line.c
index 9299b8a..4a3c853 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -465,7 +465,7 @@
 	int i;
 
 	for(i = 0; i < nlines; i++)
-		close_chan(&lines[i].chan_list, 0);
+		close_chan(&lines[i]);
 }
 
 int setup_one_line(struct line *lines, int n, char *init,