rinda/ring.rb (make_socket): do not keep socket on failures

This prevents leaked FD warnings on test/rinda/test_rinda.rb
when testing on a machine without multicast support.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57355 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rinda/ring.rb

@@ -135,7 +135,6 @@ module Rinda
 
       socket = Socket.new(addrinfo.pfamily, addrinfo.socktype,
                           addrinfo.protocol)
-      @sockets << socket
 
       if addrinfo.ipv4_multicast? or addrinfo.ipv6_multicast? then
         if Socket.const_defined?(:SO_REUSEPORT) then
@@ -166,6 +165,11 @@ module Rinda
       end
 
       socket
+    rescue
+      socket = socket.close if socket
+      raise
+    ensure
+      @sockets << socket if socket
     end
 
     ##