Replace all "Filter" field with "Filters" for consistency

In file `api/types/client.go`, some of the "*Options{}" structs own a
`Filters` field while some else have the name of `Filter`, this commit
will rename all `Filter` to `Filters` for consistency. Also `Filters`
is consistent with API with format `/xxx?filters=xxx`, that's why
`Filters` is the right name.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>

container_list.go

@@ -34,8 +34,8 @@ func (cli *Client) ContainerList(ctx context.Context, options types.ContainerLis
 		query.Set("size", "1")
 	}
 
-	if options.Filter.Len() > 0 {
-		filterJSON, err := filters.ToParamWithVersion(cli.version, options.Filter)
+	if options.Filters.Len() > 0 {
+		filterJSON, err := filters.ToParamWithVersion(cli.version, options.Filters)
 
 		if err != nil {
 			return nil, err

container_list_test.go

@@ -85,7 +85,7 @@ func TestContainerList(t *testing.T) {
 		Size:    true,
 		All:     true,
 		Since:   "container",
-		Filter: filters,
+		Filters: filters,
 	})
 	if err != nil {
 		t.Fatal(err)

node_list.go

@@ -14,8 +14,8 @@ import (
 func (cli *Client) NodeList(ctx context.Context, options types.NodeListOptions) ([]swarm.Node, error) {
 	query := url.Values{}
 
-	if options.Filter.Len() > 0 {
-		filterJSON, err := filters.ToParam(options.Filter)
+	if options.Filters.Len() > 0 {
+		filterJSON, err := filters.ToParam(options.Filters)
 
 		if err != nil {
 			return nil, err

node_list_test.go

@@ -45,7 +45,7 @@ func TestNodeList(t *testing.T) {
 		},
 		{
 			options: types.NodeListOptions{
-				Filter: filters,
+				Filters: filters,
 			},
 			expectedQueryParams: map[string]string{
 				"filters": `{"label":{"label1":true,"label2":true}}`,

service_list.go

@@ -14,8 +14,8 @@ import (
 func (cli *Client) ServiceList(ctx context.Context, options types.ServiceListOptions) ([]swarm.Service, error) {
 	query := url.Values{}
 
-	if options.Filter.Len() > 0 {
-		filterJSON, err := filters.ToParam(options.Filter)
+	if options.Filters.Len() > 0 {
+		filterJSON, err := filters.ToParam(options.Filters)
 		if err != nil {
 			return nil, err
 		}

service_list_test.go

@@ -45,7 +45,7 @@ func TestServiceList(t *testing.T) {
 		},
 		{
 			options: types.ServiceListOptions{
-				Filter: filters,
+				Filters: filters,
 			},
 			expectedQueryParams: map[string]string{
 				"filters": `{"label":{"label1":true,"label2":true}}`,

task_list.go

@@ -14,8 +14,8 @@ import (
 func (cli *Client) TaskList(ctx context.Context, options types.TaskListOptions) ([]swarm.Task, error) {
 	query := url.Values{}
 
-	if options.Filter.Len() > 0 {
-		filterJSON, err := filters.ToParam(options.Filter)
+	if options.Filters.Len() > 0 {
+		filterJSON, err := filters.ToParam(options.Filters)
 		if err != nil {
 			return nil, err
 		}

task_list_test.go

@@ -45,7 +45,7 @@ func TestTaskList(t *testing.T) {
 		},
 		{
 			options: types.TaskListOptions{
-				Filter: filters,
+				Filters: filters,
 			},
 			expectedQueryParams: map[string]string{
 				"filters": `{"label":{"label1":true,"label2":true}}`,