bpf, selftests: Add ringbuf memory type confusion test

mainline inclusion
from mainline-v5.17-rc1
commit 37c8d480
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4WT90
CVE: CVE-2021-4204

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=37c8d4807d1b8b521b30310dce97f6695dc2c2c6



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Add two tests, one which asserts that ring buffer memory can be passed to
other helpers for populating its entry area, and another one where verifier
rejects different type of memory passed to bpf_ringbuf_submit().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Reviewed-by: Kuohai Xu <xukuohai@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>