[PATCH v2] lib: optimize cpumask_next_and()

[Clement Courbet <courbet@xxxxxxxxxx>]

Hi Alexey,

> Gentoo ships 5.4.0 which doesn't inline this code on x86_64 defconfig
> (which has OPTIMIZE_INLINING).

I have not actually marked _find_next_bit() inline, it just turns out
that my compiler inlines it.
I've tried out marking the function inline and OPTIMIZE_INLINING does
not un-inline it. I'll send a v4 with an explicit inine.