benchmark: don't use template strings
benchmark: don't use template strings

When running benchmark/compare.js, it is typical to run a version of
node that does not support template strings. This provides backwards
compatibility for comparing benchmarks using older versions of node.

PR-URL: https://github.com/iojs/io.js/pull/714
Reviewed-By: Chris Dickinson <38a75c4c4f5646d63b752460df745c5b937b7e58@gmail.com>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node