members_v2 has dynamically resizable entries so that we can extend
bch_member. The members can no longer be accessed with simple array
indexing Instead members_v2_get is used to find a member's exact
location within the array and returns a copy of that member.
Alternatively member_v2_get_mut retrieves a mutable point to a member.
Signed-off-by: Hunter Shaffer <huntershaffer182456@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>