um: remove dead code

GCC 4.6's -Wunused-but-set-variable found some dead code.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/drivers/chan_kern.c

@@ -543,11 +543,10 @@ int parse_chan_pair(char *str, struct line *line, int device,
 		    const struct chan_opts *opts, char **error_out)
 {
 	struct list_head *chans = &line->chan_list;
-	struct chan *new, *chan;
+	struct chan *new;
 	char *in, *out;
 
 	if (!list_empty(chans)) {
-		chan = list_entry(chans->next, struct chan, list);
 		free_chan(chans, 0);
 		INIT_LIST_HEAD(chans);
 	}