PHP Warning call-time pass-by-reference

Found this warning:

Warning: Call-time pass-by-reference has been deprecated - argument passed by value; If you would like to pass it by reference, modify the declaration of drupal_rebuild_form(). 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. However, future versions may not support this any longer.

in mm_custom_command.module lines 56,65,74

The problem is because of the '&' in front of the variable being called in the function.
That needs to be put in the function definition, not the function call itself.