Cleanup A_AttractChase and (maybe) fix another instance of #1218

There was a fair amount of redundant code here, including !2390 (merged) because the flingring works perfectly fine with attraction without needing to be transformed back into a ring.

However, there is a good reason to turn lost rings into flingrings, so they can acquire flingring physics. That code was still spawning an entirely new ring, likely resulting in another cause of #1218 (closed)