The arena_list selftest uses (1ull << 32) in the mmap address
computation for arm64. Use the same in the verifier_arena selftest.

This makes the selftest pass for arm64 on the CI[1].

[1] https://github.com/kernel-patches/bpf/pull/6622Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240322133552.70681-1-puranjay12@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>