lib: bpf_legacy: fix missing socket close when connect() fails

lib: bpf_legacy: fix missing socket close when connect() fails

In functions bpf_{send,recv}_map_fds(), when connect fails after a
socket is successfully opened, we return with error missing a close on
the socket.

Fix this closing the socket if opened and using a single return point
for both the functions.

Fixes: 6256f8c9e45f ("tc, bpf: finalize eBPF support for cls and act front-end")
Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>