Added return value for the node_init

- Can be used as before, but cleaner interface in parser.y

exercises/02/vslc/src/tree.c

@@ -20,7 +20,8 @@ print_syntax_tree ( void )
 }
 
 
-void
+// Changed so it returns the pointer to the new node, can be used as before, but makes the parser file cleaner
+node_t*
 node_init (node_t *nd, node_index_t type, void *data, uint64_t n_children, ...)
 {
     // Copy the type
@@ -45,6 +46,8 @@ node_init (node_t *nd, node_index_t type, void *data, uint64_t n_children, ...)
     // Populate the memory with pointers to children
     for (int i = 0; i < n_children; i++)
         nd->children[i] = va_arg(list_children, node_t*);
+
+    return nd;
 }