MINOR: tcp: replace tcp_src_to_stktable_key with addr_to_stktable_key

Make it more obvious that this function does not depend on any knowledge
of the session. This is important to plan for TCP rules that can run on
connection without any initialized session yet.
diff --git a/src/session.c b/src/session.c
index 774a8a3..db13fc6 100644
--- a/src/session.c
+++ b/src/session.c
@@ -2369,7 +2369,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2429,7 +2429,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2490,7 +2490,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2546,7 +2546,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2607,7 +2607,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2627,7 +2627,7 @@
 	struct stktable_key *key;
 	void *ptr;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2696,7 +2696,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2752,7 +2752,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2813,7 +2813,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2869,7 +2869,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2930,7 +2930,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -2986,7 +2986,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -3047,7 +3047,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -3108,7 +3108,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -3171,7 +3171,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -3232,7 +3232,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;
 
@@ -3295,7 +3295,7 @@
 {
 	struct stktable_key *key;
 
-	key = tcp_src_to_stktable_key(l4);
+	key = addr_to_stktable_key(&l4->si[0].conn.addr.from);
 	if (!key)
 		return 0;