Merge branch 'bpf-cleanup-btf-raw-tp'

Alexei Starovoitov says:

====================
v1->v2: addressed Andrii's feedback

When BTF-enabled raw_tp were introduced the plan was to follow up
with BTF-enabled kprobe and kretprobe reusing PROG_RAW_TRACEPOINT
and PROG_KPROBE types. But k[ret]probe expect pt_regs while
BTF-enabled program ctx will be the same as raw_tp.
kretprobe is indistinguishable from kprobe while BTF-enabled
kretprobe will have access to retval while kprobe will not.
Hence PROG_KPROBE type is not reusable and reusing
PROG_RAW_TRACEPOINT no longer fits well.
Hence introduce 'umbrella' prog type BPF_PROG_TYPE_TRACING
that will cover different BTF-enabled tracing attach points.
The changes make libbpf side cleaner as well.
check_attach_btf_id() is cleaner too.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>