Clang 10 warns about unused results of relational operators, which is
where this is coming from.
Fix by adding the usual prefix
[[maybe_unused]] auto r = ~~~;
to silence the warning. Do this elsewhere, too, since [[nodiscard]] is
slowly being rolled out across all our APIs. This is not a complete
sweep, though.
Not picking to 5.15, because this pattern doesn't work there and I
don't want to introduce a new one.
Pick-to: 6.3 6.2
Change-Id: I40dd8ad07496b686979dce533e044cbb486e30f3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>