CONNECTION: Track the connection state and callback via the context structure

Dont free the connection state when login is finished, instead track it via the
iscsi context structure and free it once the context is destroyed

lib/init.c

@@ -244,6 +244,9 @@ iscsi_destroy_context(struct iscsi_context *iscsi)
 	free(discard_const(iscsi->chap_c));
 	iscsi->chap_c = NULL;
 
+	free(iscsi->connect_data);
+	iscsi->connect_data = NULL;
+
 	free(iscsi);
 
 	return 0;