I can change it, sure, but it's a matter of taste. To me the above asks
"does the value change when it is truncated to a u16" which makes
perfect sense when the value is next used with iowrite16be(). Using a
comparison to U16_MAX takes more brain cycles for me, because I have to
think whether it should be > or >=, and are there some
signedness/integer promotion business interfering with that test.