Warning: Call-time pass-by-reference has been deprecated

This warning appears on every page:

Warning: Call-time pass-by-reference has been deprecated; If you would like to pass it by reference, modify the declaration of [runtime function name](). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file in /home/.jojo/[user]/[mysite.com]/sites/all/modules/ad/report/ad_report.module on line 229

On that line I got rid of the error by changing it from:
$output .= ad_report_admin_ad_table(strtotime($start), strtotime($end), $group, FALSE, &$ads);

to:
$output .= ad_report_admin_ad_table(strtotime($start), strtotime($end), $group, FALSE, $ads);

So I just removed that ampersand and now the error is gone and everything seems to be working, but I have no idea if what I did was correct.