selftests/bpf: add missing executables to .gitignore

Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/.gitignore

@@ -19,3 +19,7 @@ test_btf
 test_sockmap
 test_lirc_mode2_user
 get_cgroup_id_user
+test_skb_cgroup_id_user
+test_socket_cookie
+test_cgroup_storage
+test_select_reuseport