Remove unnecessary cast from clamp computation. (dart-lang/clock#21)

Now that the analyzer correctly computes the type of `int.clamp(int,
int)` as `int` (for libraries opted into null safety), we no longer
need to cast the result to an `int`.
1 file changed
tree: ad31cb92158c54b1e858e7b9bd5ac3d0ebf256d3
  1. pkgs/