tools/bpf: fix two test_btf unit test cases

tools/bpf: fix two test_btf unit test cases

[ Upstream commit 8800cd031af085807028656c6ba7eb7908d78262 ]

There are two unit test cases, which should encode
TYPEDEF type, but instead encode PTR type.
The error is flagged out after enforcing name
checking in the previous patch.

Fixes: c0fa1b6c3efc ("bpf: btf: Add BTF tests")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>