Add nakedret linter.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

cli/command/container/prune.go

@@ -52,12 +52,12 @@ func runPrune(dockerCli command.Cli, options pruneOptions) (spaceReclaimed uint6
 	pruneFilters := command.PruneFilters(dockerCli, options.filter.Value())
 
 	if !options.force && !command.PromptForConfirmation(dockerCli.In(), dockerCli.Out(), warning) {
-		return
+		return 0, "", nil
 	}
 
 	report, err := dockerCli.Client().ContainersPrune(context.Background(), pruneFilters)
 	if err != nil {
-		return
+		return 0, "", err
 	}
 
 	if len(report.ContainersDeleted) > 0 {
@@ -68,7 +68,7 @@ func runPrune(dockerCli command.Cli, options pruneOptions) (spaceReclaimed uint6
 		spaceReclaimed = report.SpaceReclaimed
 	}
 
-	return
+	return spaceReclaimed, output, nil
 }
 
 // RunPrune calls the Container Prune API

cli/command/container/stats_helpers.go

@@ -200,7 +200,8 @@ func calculateCPUPercentWindows(v *types.StatsJSON) float64 {
 	return 0.00
 }
 
-func calculateBlockIO(blkio types.BlkioStats) (blkRead uint64, blkWrite uint64) {
+func calculateBlockIO(blkio types.BlkioStats) (uint64, uint64) {
+	var blkRead, blkWrite uint64
 	for _, bioEntry := range blkio.IoServiceBytesRecursive {
 		switch strings.ToLower(bioEntry.Op) {
 		case "read":
@@ -209,7 +210,7 @@ func calculateBlockIO(blkio types.BlkioStats) (blkRead uint64, blkWrite uint64)
 			blkWrite = blkWrite + bioEntry.Value
 		}
 	}
-	return
+	return blkRead, blkWrite
 }
 
 func calculateNetwork(network map[string]types.NetworkStats) (float64, float64) {