libbpf: Bump libpf current version to v0.0.8

New development cycles starts, bump to v0.0.8.
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/158220518424.127661.8278643006567775528.stgit@xdp-tutorial

tools/lib/bpf/libbpf.map

@@ -235,3 +235,6 @@ LIBBPF_0.0.7 {
 		btf__align_of;
 		libbpf_find_kernel_btf;
 } LIBBPF_0.0.6;
+
+LIBBPF_0.0.8 {
+} LIBBPF_0.0.7;