small change in `select` example. (#2345)
small change in `select` example. (#2345)

In the previous example one future always finished first (because of
implementation details), possibly confusing users about what `select`
does.

This commit resolves the issue by being explicit about one future
finishing before the other.

Co-authored-by: tungli <72fec05ee2db575d765b0bda3c952d552ace408c@mail.muni.cz>
Co-authored-by: Taiki Endo <715e282f31bedfd1c458601f40996127b7725db2@gmail.com>
alexcrichton/futures-rs