extractor: use bpf_probe_read_user_str() instead of bpf_probe_read_str()

[0xB10C]

peer-observer/extractor/src/bpf/tracing.bpf.c

Lines 77 to 79 in df2e85d

	bpf_probe_read_str(&meta->addr, sizeof(meta->addr), addr);
	bpf_probe_read_str(&meta->conn_type, sizeof(meta->conn_type), conn_type);
	bpf_probe_read_str(&meta->msg_type, sizeof(meta->msg_type), msg_type);

In multiple places, we use bpf_probe_read_str. https://man7.org/linux/man-pages/man7/bpf-helpers.7.html recommends to use bpf_probe_read_user_str instead.

Generally, use bpf_probe_read_user_str() or bpf_probe_read_kernel_str() instead.