Pull percpu updates from Dennis Zhou:
"A couple of updates to clean up the code with no change in behavior"
* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
percpu: Use struct_size() helper
percpu: fix typo in pcpu_setup_first_chunk() comment
percpu: Make pcpu_setup_first_chunk() void function