selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test

[ Upstream commit b8e188f0 ]

The assumption of 'in privileged mode reads from uninitialized stack locations
are permitted' is not quite correct since the verifier was probing for read
access rather than write access. Both tests need to be annotated as __success
for privileged and unprivileged.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240913191754.13290-6-daniel@iogearbox.net


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