Pull flex-array size helper from Kees Cook:
"During the treewide clean-ups of zero-length "flexible arrays", the
struct_size() helper was heavily used, but it was noticed that many
times it would have been nice to have an additional helper to get the
size of just the flexible array itself.
This need appears to be even more common when cleaning up the 1-byte
array "flexible arrays", so Gustavo implemented it.
I'd love to get this landed early so it can be used during the v5.9
dev cycle to ease the 1-byte array cleanups."
* tag 'overflow-v5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
overflow.h: Add flex_array_size() helper