bgpd: removed unused parameter from bgp_dump_attr()

bgpd: removed unused parameter from bgp_dump_attr()

Originally we used the 'peer' parameter for this:

  if (peer_sort (peer) == BGP_PEER_IBGP)
    snprintf (buf + strlen (buf), size - strlen (buf), ", localpref %d",
              attr->local_pref);

Now we have this:

  if (CHECK_FLAG (attr->flag, ATTR_FLAG_BIT (BGP_ATTR_LOCAL_PREF)))
    snprintf (buf + strlen (buf), size - strlen (buf), ", localpref %u",
              attr->local_pref);

Remove the now useless 'peer' parameter.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>