decorate --env-file, --label-file errors

Before:

    docker run --rm --env-file=./no-such-file alpine
    docker: open ./no-such-file: no such file or directory

    Run 'docker run --help' for more information

After:

    docker run --rm --env-file=./no-such-file alpine
    docker: --env-file: open ./no-such-file: no such file or directory

    Run 'docker run --help' for more information

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

cli/command/container/opts.go

@@ -506,13 +506,13 @@ func parse(flags *pflag.FlagSet, copts *containerOptions, serverOS string) (*con
 	// collect all the environment variables for the container
 	envVariables, err := opts.ReadKVEnvStrings(copts.envFile.GetSlice(), copts.env.GetSlice())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("--env-file: %w", err)
 	}
 
 	// collect all the labels for the container
 	labels, err := opts.ReadKVStrings(copts.labelsFile.GetSlice(), copts.labels.GetSlice())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("--label-file: %w", err)
 	}
 
 	pidMode := container.PidMode(copts.pidMode)