Don't buffer the output in non-verbose mode
Don't buffer the output in non-verbose mode

Bazel run doesn't currently attach the program to the terminal, so the
C library thinks it should buffer the output. However, that makes the
output a bit confusing (for a benchmark) because it all shows up at
the same time.

ulfjack/ryu,ulfjack/ryu,ulfjack/ryu,ulfjack/ryu