tc: act_bpf: fix memory leak

prog->bpf_ops is populated when act_bpf is used with classic BPF and
prog->bpf_name is optionally used with extended BPF.
Fix memory leak when act_bpf is released.

Fixes: d23b8ad8 ("tc: add BPF based action")
Fixes: a8cb5f55 ("act_bpf: add initial eBPF support for actions")
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>