writer: Fixed a minor var error
writer: Fixed a minor var error

Former-commit-id: c25c0ab6c2649dd9279466304a0123f22d97cebd [formerly c25c0ab6c2649dd9279466304a0123f22d97cebd [formerly a77464cb386b2dabbbf52bb0af721082e3c7ab95]]
Former-commit-id: 3614e027976d56e1e2a66d1aeee26715ab3f5c70
Former-commit-id: 7ffe8d710b561e363d995f9532e4c9151b3dd5f7
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine