fix errors spotted by usage analysis

ipam/ring/ring.go

@@ -447,10 +447,7 @@ func (ws weightedPeers) Swap(i, j int)      { ws[i], ws[j] = ws[j], ws[i] }
 // ChoosePeersToAskForSpace returns all peers we can ask for space in
 // the range [start, end), in weighted-random order.  Assumes start<end.
 func (r *Ring) ChoosePeersToAskForSpace(start, end address.Address) []mesh.PeerName {
-	var (
-		sum               address.Offset
-		totalSpacePerPeer = make(map[mesh.PeerName]address.Offset) // Compute total free space per peer
-	)
+	totalSpacePerPeer := make(map[mesh.PeerName]address.Offset)
 
 	// iterate through tokens
 	for i, entry := range r.Entries {
@@ -472,7 +469,6 @@ func (r *Ring) ChoosePeersToAskForSpace(start, end address.Address) []mesh.PeerN
 		}
 
 		totalSpacePerPeer[entry.Peer] += entry.Free
-		sum += entry.Free
 	}
 
 	// Compute weighted random numbers, then sort.

ipam/space/space_test.go

@@ -155,7 +155,7 @@ func TestSpaceFree(t *testing.T) {
 	// Check we are full
 	ok, _ := space.Allocate(entireRange)
 	require.True(t, !ok, "Should have failed to get address")
-	r, ok = space.Donate(entireRange)
+	r, _ = space.Donate(entireRange)
 	require.True(t, r.Size() == 0, "Wrong space")
 
 	// Free in the middle

prog/plugin/main.go

@@ -51,7 +51,6 @@ func main() {
 	Log.Println("Weave plugin", version, "Command line options:", os.Args[1:])
 	Log.Info(dockerClient.Info())
 
-	var globalListener, meshListener net.Listener
 	endChan := make(chan error, 1)
 	if address != "" {
 		globalListener, err := listenAndServe(dockerClient, address, nameserver, noMulticastRoute, endChan, "global", false)
@@ -71,8 +70,6 @@ func main() {
 	err = <-endChan
 	if err != nil {
 		Log.Errorf("Error from listener: %s", err)
-		globalListener.Close()
-		meshListener.Close()
 		os.Exit(1)
 	}
 }