Fix a warning from UBSAN

I won't pretend I understand what UBSAN is really trying to tell me
here, but that assignment can be rewritten in a way which does not cause
the following warning:

 libyang/src/tree_data.c:5564:19: runtime error: member access within address 0x60600005c7e0 with insufficient space for an object of type 'struct lyd_node'
 0x60600005c7e0: note: pointer points here
  1c 00 00 26  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00
               ^

Fixes: sysrepo/sysrepo#2295

src/tree_data.c

@@ -5561,7 +5561,7 @@ _lyd_dup_node(const struct lyd_node *node, const struct lys_node *schema, struct
         new_any = calloc(1, sizeof *new_any);
         new_node = (struct lyd_node *)new_any;
         LY_CHECK_ERR_GOTO(!new_node, LOGMEM(ctx), error);
-        new_node->schema = (struct lys_node *)schema;
+        new_any->schema = (struct lys_node *)schema;
 
         if (_lyd_dup_node_common(new_node, node, ctx, options)) {
             goto error;