samples/bpf: detach prog from cgroup

test_cgrp2_sock.sh and test_cgrp2_sock2.sh tests keep the program
attached to cgroup even after completion.
Using detach functionality of test_cgrp2_sock in both scripts.

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/samples/bpf/test_cgrp2_sock.sh b/samples/bpf/test_cgrp2_sock.sh
index 8ee0371a..9f61742 100755
--- a/samples/bpf/test_cgrp2_sock.sh
+++ b/samples/bpf/test_cgrp2_sock.sh
@@ -61,6 +61,7 @@
 
 	[ -n "$msg" ] && echo "ERROR: $msg"
 
+	test_cgrp2_sock -d ${CGRP_MNT}/sockopts
 	ip li del cgrp2_sock
 	umount ${CGRP_MNT}