libbpf-tools: Update bpftool submodule

Closes #4200.

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>
diff --git a/libbpf-tools/bpftool b/libbpf-tools/bpftool
index 04c465f..6eb3e20 160000
--- a/libbpf-tools/bpftool
+++ b/libbpf-tools/bpftool
@@ -1 +1 @@
-Subproject commit 04c465fd1f561f67796dc68bbfe1aa7cfa956c3c
+Subproject commit 6eb3e20583da834da18ea3011dcefd08b3493f8d