ethtool: eeprom: fix null-deref on genl_info in dump

The similar fix as commit 46cdedf ("ethtool: pse-pd: fix null-deref on
genl_info in dump") is also needed for ethtool eeprom.

Fixes: c781ff1 ("ethtool: Allow network drivers to dump arbitrary EEPROM data")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/5575919a2efc74cd9ad64021880afc3805c54166.1666362167.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/ethtool/eeprom.c

@@ -124,7 +124,7 @@ static int eeprom_prepare_data(const struct ethnl_req_info *req_base,
 	if (ret)
 		goto err_free;
 
-	ret = get_module_eeprom_by_page(dev, &page_data, info->extack);
+	ret = get_module_eeprom_by_page(dev, &page_data, info ? info->extack : NULL);
 	if (ret < 0)
 		goto err_ops;