samples: Bluetooth: Add missing bt_conn_ref for a few samples

Some samples were missing a call to bt_conn_ref when assigning
default_conn.

Signed-off-by: Emil Gydesen <[email protected]>

Author: Thalley

samples/bluetooth/iso_connected_benchmark/src/main.c

@@ -426,7 +426,7 @@ static void connected(struct bt_conn *conn, uint8_t err)
 		default_conn = NULL;
 		return;
 	} else if (role == ROLE_PERIPHERAL) {
-		default_conn = conn;
+		default_conn = bt_conn_ref(conn);
 	}
 
 	LOG_INF("Connected: %s", addr);

samples/bluetooth/peripheral_past/src/main.c

@@ -79,7 +79,7 @@ static void connected(struct bt_conn *conn, uint8_t err)
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
 	if (default_conn == NULL) {
-		default_conn = conn;
+		default_conn = bt_conn_ref(conn);
 	}
 
 	if (conn != default_conn) {

samples/bluetooth/unicast_audio_server/src/main.c

@@ -222,7 +222,7 @@ static void connected(struct bt_conn *conn, uint8_t err)
 	}
 
 	printk("Connected: %s\n", addr);
-	default_conn = conn;
+	default_conn = bt_conn_ref(conn);
 }
 
 static void disconnected(struct bt_conn *conn, uint8_t reason)