net/ipv4/ipv6: Replace one-element array with flexible-array member

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure.  Kernel code
should always use “flexible array members”[1] for these cases.  The
older style of one-element or zero-length arrays should no longer be
used[2].

Refactor the code according to the use of a flexible-array member in
struct group_filter, instead of a one-element array.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
3 files changed