MINOR: channel: rename function chn_sess to chn_strm

The name of the function chn_sess is no longer appropriate.
This patch renames it to chn_strm.
diff --git a/include/proto/channel.h b/include/proto/channel.h
index b1c313c..733f9d2 100644
--- a/include/proto/channel.h
+++ b/include/proto/channel.h
@@ -55,7 +55,7 @@
 
 
 /* returns a pointer to the stream the channel belongs to */
-static inline struct stream *chn_sess(const struct channel *chn)
+static inline struct stream *chn_strm(const struct channel *chn)
 {
 	if (chn->flags & CF_ISRESP)
 		return LIST_ELEM(chn, struct stream *, res);
diff --git a/src/stream.c b/src/stream.c
index 5583d1d..deb51e8 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -365,7 +365,7 @@
 	if (!(chn->flags & CF_ISRESP))
 		margin = global.tune.reserved_bufs;
 
-	s = chn_sess(chn);
+	s = chn_strm(chn);
 
 	b = b_alloc_margin(&chn->buf, margin);
 	if (b)