99-time.js: Use `shellPrint` instead of `printjson`
99-time.js: Use `shellPrint` instead of `printjson`

This ensures correct output when using `time` with commands that return objects
that use a `.shellPrint()` method to correctly output in the shell, eg: before
this fix, `time db.foo.find()` did not output the same as `db.foo.find()`.

devkev/mongorcd