sync to latest libbpf repo

sync with latest libbpf repo

Signed-off-by: Yonghong Song <yhs@fb.com>
diff --git a/introspection/bps.c b/introspection/bps.c
index 5ac8099..fe47a80 100644
--- a/introspection/bps.c
+++ b/introspection/bps.c
@@ -41,6 +41,7 @@
   [BPF_PROG_TYPE_FLOW_DISSECTOR] = "flow_dissector",
   [BPF_PROG_TYPE_CGROUP_SYSCTL] = "cgroup_sysctl",
   [BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE] = "raw_tracepoint_writable",
+  [BPF_PROG_TYPE_CGROUP_SOCKOPT] = "cgroup_sockopt",
 };
 
 static const char * const map_type_strings[] = {