Hide [flags] in usage output

This patch hides the [flags] in the usage output of commands, using the
new `.DisableFlagsInUseLine` option, instead of the temporary workaround
added in 8e600e10f7

Before this change:

    docker run
    "docker run" requires at least 1 argument.
    See 'docker run --help'.

    Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...] [flags]

    Run a command in a new container

After this change:

    docker run
    "docker run" requires at least 1 argument.
    See 'docker run --help'.

    Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

    Run a command in a new container

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Upstream-commit: 00d080269a
Component: cli

components/cli/docs/yaml/yaml.go

@@ -8,7 +8,6 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/docker/cli/cli"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	yaml "gopkg.in/yaml.v2"
@@ -96,7 +95,7 @@ func GenYamlCustom(cmd *cobra.Command, w io.Writer) error {
 	}
 
 	if cmd.Runnable() {
-		cliDoc.Usage = cli.UseLine(cmd)
+		cliDoc.Usage = cmd.UseLine()
 	}
 
 	if len(cmd.Example) > 0 {