bpf, sparc: remove unused variable

Since fe83963b ("bpf, sparc64: remove ld_abs/ld_ind") it's not
used anymore therefore remove it.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>