um: sorting out the chan mess, part 1

put references to in and out chans associated with line into
explicit struct chan * fields in it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/drivers/chan_kern.c

@@ -547,6 +547,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 	char *in, *out;
 
 	if (!list_empty(chans)) {
+		line->chan_in = line->chan_out = NULL;
 		free_chan(chans);
 		INIT_LIST_HEAD(chans);
 	}
@@ -565,6 +566,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 
 		new->input = 1;
 		list_add(&new->list, chans);
+		line->chan_in = new;
 
 		new = parse_chan(line, out, device, opts, error_out);
 		if (new == NULL)
@@ -572,6 +574,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 
 		list_add(&new->list, chans);
 		new->output = 1;
+		line->chan_out = new;
 	}
 	else {
 		new = parse_chan(line, str, device, opts, error_out);
@@ -581,6 +584,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 		list_add(&new->list, chans);
 		new->input = 1;
 		new->output = 1;
+		line->chan_in = line->chan_out = new;
 	}
 	return 0;
 }

arch/um/drivers/line.h

@@ -39,6 +39,7 @@ struct line {
 
 	char *init_str;
 	struct list_head chan_list;
+	struct chan *chan_in, *chan_out;
 
 	/*This lock is actually, mostly, local to*/
 	spinlock_t lock;