MINOR: protocols: replace protocol_by_family() with protocol_lookup()

At a few places we were still using protocol_by_family() instead of
the richer protocol_lookup(). The former is limited as it enforces
SOCK_STREAM and a stream protocol at the control layer. At least with
protocol_lookup() we don't have this limitationn. The values were still
set for now but later we can imagine making them configurable on the
fly.
diff --git a/include/haproxy/protocol.h b/include/haproxy/protocol.h
index 0c52bf7..05bba78 100644
--- a/include/haproxy/protocol.h
+++ b/include/haproxy/protocol.h
@@ -76,16 +76,6 @@
  */
 int protocol_enable_all(void);
 
-/* returns the protocol associated to family <family> with sock_type and
- * ctrl_type of SOCK_STREAM, or NULL if not found
- */
-static inline struct protocol *protocol_by_family(int family)
-{
-	if (family >= 0 && family < AF_CUST_MAX)
-		return __protocol_by_family[family][0][0];
-	return NULL;
-}
-
 /* returns the protocol associated to family <family> with proto_type among the
  * supported protocol types, and ctrl_type of either SOCK_STREAM or SOCK_DGRAM
  * depending on the requested values, or NULL if not found.
diff --git a/src/backend.c b/src/backend.c
index f170cb4..ee6e2b8 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1542,7 +1542,7 @@
 	if (!srv_conn->xprt) {
 		/* set the correct protocol on the output stream interface */
 		if (srv) {
-			if (conn_prepare(srv_conn, protocol_by_family(srv_conn->dst->ss_family), srv->xprt)) {
+			if (conn_prepare(srv_conn, protocol_lookup(srv_conn->dst->ss_family, PROTO_TYPE_STREAM, 0), srv->xprt)) {
 				conn_free(srv_conn);
 				return SF_ERR_INTERNAL;
 			}
@@ -1550,7 +1550,7 @@
 			int ret;
 
 			/* proxies exclusively run on raw_sock right now */
-			ret = conn_prepare(srv_conn, protocol_by_family(srv_conn->dst->ss_family), xprt_get(XPRT_RAW));
+			ret = conn_prepare(srv_conn, protocol_lookup(srv_conn->dst->ss_family, PROTO_TYPE_STREAM, 0), xprt_get(XPRT_RAW));
 			if (ret < 0 || !(srv_conn->ctrl)) {
 				conn_free(srv_conn);
 				return SF_ERR_INTERNAL;
diff --git a/src/cfgparse.c b/src/cfgparse.c
index ed5efda..58067c8 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -918,7 +918,7 @@
 		 */
 		if (peer || !local_peer) {
 			newpeer->addr = curpeers->peers_fe->srv->addr;
-			newpeer->proto = protocol_by_family(newpeer->addr.ss_family);
+			newpeer->proto = protocol_lookup(newpeer->addr.ss_family, PROTO_TYPE_STREAM, 0);
 		}
 
 		newpeer->xprt  = xprt_get(XPRT_RAW);
diff --git a/src/resolvers.c b/src/resolvers.c
index a8d374e..a806f33 100644
--- a/src/resolvers.c
+++ b/src/resolvers.c
@@ -3417,7 +3417,7 @@
 
 			set_host_port(sk, 53);
 
-			proto = protocol_by_family(sk->ss_family);
+			proto = protocol_lookup(sk->ss_family, PROTO_TYPE_STREAM, 0);
 			if (!proto || !proto->connect) {
 				ha_warning("parsing [/etc/resolv.conf:%d] : '%s' : connect() not supported for this address family.\n",
 					   resolv_linenum, address);
diff --git a/src/server.c b/src/server.c
index f74bb5c..7b702f5 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2558,7 +2558,8 @@
 		 */
 		srv_set_addr_desc(newsrv, !(parse_flags & SRV_PARSE_DYNAMIC));
 
-		if (!newsrv->srvrq && !newsrv->hostname && !protocol_by_family(newsrv->addr.ss_family)) {
+		if (!newsrv->srvrq && !newsrv->hostname &&
+		    !protocol_lookup(newsrv->addr.ss_family, PROTO_TYPE_STREAM, 0)) {
 			ha_alert("Unknown protocol family %d '%s'\n",
 			         newsrv->addr.ss_family, args[*cur_arg]);
 			err_code |= ERR_ALERT | ERR_FATAL;
diff --git a/src/tcpcheck.c b/src/tcpcheck.c
index 133dfe5..14f83ea 100644
--- a/src/tcpcheck.c
+++ b/src/tcpcheck.c
@@ -1125,7 +1125,7 @@
 	*conn->dst = (is_addr(&connect->addr)
 		      ? connect->addr
 		      : (is_addr(&check->addr) ? check->addr : s->addr));
-	proto = protocol_by_family(conn->dst->ss_family);
+	proto = protocol_lookup(conn->dst->ss_family, PROTO_TYPE_STREAM, 0);
 
 	port = 0;
 	if (connect->port)