Merged in another test fix

Otherwise I get

Error: test_massively_parallel_IP_address_addition(TestAddr::TestWithNetlinkRouteSocket)
  Errno::EMFILE: Too many open files - socket(2)
  lib/linux/netlink/nlsocket.rb:61:in `initialize'
  lib/linux/netlink/nlsocket.rb:61:in `new'
  lib/linux/netlink/nlsocket.rb:61:in `initialize'
  lib/linux/netlink/route.rb:21:in `initialize'
  test/t_route.rb:54:in `new'
  test/t_route.rb:54:in `block (4 levels) in <class:TestAddr>'

test/t_route.rb

@@ -42,8 +42,12 @@ class TestAddr < Test::Unit::TestCase
 
     test "massively parallel IP address addition" do
       @ifname = create_test_interface
+      return if @ifname.nil?
       
-      ips = (10..20).map {|y| (1..254).map {|z| "10.100.#{y}.#{z}" } }.flatten.compact
+      link = @ip.link.list.find{|x| x.ifname == @ifname} 
+      return if link.nil?
+
+      ips = (10..13).map {|y| (1..254).map {|z| "10.100.#{y}.#{z}" } }.flatten.compact
 
       threads = ips.map {|ip|
         Thread.new {
@@ -55,7 +59,8 @@ class TestAddr < Test::Unit::TestCase
         }
       }
 
-      threads.map(&:join)
+      threads.map{|t| t.join }
+
       created = @ip.addr.list(:index => @ifname, :family => Socket::AF_INET).
         map {|ifaddr| ifaddr.address.to_s }