[C++] Fix err_empty_var_name.mk
[C++] Fix err_empty_var_name.mk

pombredanne/kati,dalinaum/kati,dalinaum/kati,google/kati,pombredanne/kati,google/kati,google/kati,dalinaum/kati,google/kati,shinh/kati,dalinaum/kati,shinh/kati,pombredanne/kati,colincross/kati,danw/kati,shinh/kati,colincross/kati,shinh/kati,colincross/kati,danw/kati,google/kati,pombredanne/kati,pombredanne/kati,shinh/kati,colincross/kati,colincross/kati,danw/kati,danw/kati,danw/kati,danw/kati,pombredanne/kati,colincross/kati,dalinaum/kati,shinh/kati