Fix spin_wait::spin_one() on Windows platforms
Fix spin_wait::spin_one() on Windows platforms

A conditional was accidentally inverted which meant that the spin-wait
would first start yielding to the OS and then later start spinning with
very large loopCount values, potentially leading to large pauses.

Originally fixed by @loopunit in https://github.com/loopunit/cppcoro/commit/242db2b0f6d2c485e3f869b284ff1962071b1eba
lewissbaker/cppcoro,lewissbaker/cppcoro,lewissbaker/cppcoro,lewissbaker/cppcoro