bpf: allow to disable bpf prog memory accounting

We can simply disable the bpf prog memory accouting by not setting the
GFP_ACCOUNT.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Link: https://lore.kernel.org/r/20230210154734.4416-5-laoar.shao@gmail.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>