Well if this is deep deep down in a nested loop, then either you increase char or you wrap that code into multiple statements. It would be counterproductive if this is first or second level.

However, I think I missed one important point. If you are writing for Linux kernel, then 80 chars is definitely not enough since 8 spaces = 1 tab in kernel code. That is, if you have a deep branching, then after 2-3 levels 80 chars wouldn't be enough. But increasing to 100 is only going to help for an extra level.

So the important point missing is the char limit is often project coding style dependent.