bpf: Add more WARN_ON_ONCE checks for mismatched alloc and free

There are two possible mismatched alloc and free cases in BPF memory
allocator:

1) allocate from cache X but free by cache Y with a different unit_size
2) allocate from per-cpu cache but free by kmalloc cache or vice versa

So add more WARN_ON_ONCE checks in free_bulk() and __free_by_rcu() to
spot these mismatched alloc and free early.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231021014959.3563841-1-houtao@huaweicloud.com