CLEANUP: session: remove session_from_task()

Since commit 3dd6a25 ("MINOR: stream-int: retrieve session pointer from
stream-int"), we can get the session from the task, so let's get rid of
this less obvious function.
diff --git a/include/proto/session.h b/include/proto/session.h
index 1b3f603..fd62dfd 100644
--- a/include/proto/session.h
+++ b/include/proto/session.h
@@ -62,12 +62,6 @@
 void session_release_buffers(struct session *s);
 int session_alloc_recv_buffer(struct session *s, struct buffer **buf);
 
-/* returns the session from a void *owner */
-static inline struct session *session_from_task(struct task *t)
-{
-	return (struct session *)t->context;
-}
-
 /* sets the stick counter's entry pointer */
 static inline void stkctr_set_entry(struct stkctr *stkctr, struct stksess *entry)
 {
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 1abc7a9..a608b47 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -569,7 +569,7 @@
 static int stats_dump_table_head_to_buffer(struct chunk *msg, struct stream_interface *si,
 					   struct proxy *proxy, struct proxy *target)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 
 	chunk_appendf(msg, "# table: %s, type: %s, size:%d, used:%d\n",
 		     proxy->id, stktable_types[proxy->table.type].kw, proxy->table.size, proxy->table.current);
@@ -658,7 +658,7 @@
 
 static void stats_sock_table_key_request(struct stream_interface *si, char **args, int action)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct appctx *appctx = __objt_appctx(si->end);
 	struct proxy *px = appctx->ctx.table.target;
 	struct stksess *ts;
@@ -1061,7 +1061,7 @@
  */
 static int stats_sock_parse_request(struct stream_interface *si, char *line)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct appctx *appctx = __objt_appctx(si->end);
 	char *args[MAX_STATS_ARGS + 1];
 	int arg;
@@ -3740,7 +3740,7 @@
 static int stats_dump_proxy_to_buffer(struct stream_interface *si, struct proxy *px, struct uri_auth *uri)
 {
 	struct appctx *appctx = __objt_appctx(si->end);
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct channel *rep = si->ib;
 	struct server *sv, *svs;	/* server and server-state, server-state=server or server->track */
 	struct listener *l;
@@ -4395,7 +4395,7 @@
  */
 static int stats_process_http_post(struct stream_interface *si)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct appctx *appctx = objt_appctx(si->end);
 
 	struct proxy *px = NULL;
@@ -4714,7 +4714,7 @@
 
 static int stats_send_http_headers(struct stream_interface *si)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct uri_auth *uri = s->be->uri_auth;
 	struct appctx *appctx = objt_appctx(si->end);
 
@@ -4748,7 +4748,7 @@
 static int stats_send_http_redirect(struct stream_interface *si)
 {
 	char scope_txt[STAT_SCOPE_TXT_MAXLEN + sizeof STAT_SCOPE_PATTERN];
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct uri_auth *uri = s->be->uri_auth;
 	struct appctx *appctx = objt_appctx(si->end);
 
@@ -4798,7 +4798,7 @@
 static void http_stats_io_handler(struct stream_interface *si)
 {
 	struct appctx *appctx = __objt_appctx(si->end);
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct channel *req = si->ob;
 	struct channel *res = si->ib;
 
@@ -5747,7 +5747,7 @@
 static int stats_table_request(struct stream_interface *si, int action)
 {
 	struct appctx *appctx = __objt_appctx(si->end);
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct ebmb_node *eb;
 	int dt;
 	int skip_entry;
diff --git a/src/peers.c b/src/peers.c
index 173f784..23c4ea3 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -178,7 +178,7 @@
  */
 static void peer_session_release(struct stream_interface *si)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct appctx *appctx = objt_appctx(si->end);
 	struct peer_session *ps = (struct peer_session *)appctx->ctx.peers.ptr;
 
@@ -212,7 +212,7 @@
  */
 static void peer_io_handler(struct stream_interface *si)
 {
-	struct session *s = session_from_task(si->owner);
+	struct session *s = si_sess(si);
 	struct peers *curpeers = (struct peers *)s->fe->parent;
 	struct appctx *appctx = objt_appctx(si->end);
 	int reql = 0;