[Bug c/82437] [8 Regression] false-positive -Wtautological-compare warning with -std=gnu89

[arnd at linaro dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82437

--- Comment #3 from Arnd Bergmann <arnd at linaro dot org> ---
(In reply to Jakub Jelinek from comment #2)
> Untested fix.

This appears to address all instances of the problem for me, thanks!