[BUG] Description - generated code is giving lint errors

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Generated code is not lint safe, the below yaml (multipart file attachment), generates code like:

**os.File is reported as a 'gofmt' linting error

type ApiV7ValidatePostRequest struct {
	ctx context.Context
	ApiService *UserJourneyApiService
	journey **os.File
}

ALSO, in the execute function, lint reports it as 'errcheck' linting error (returned error is not checked)

fbs, _ := ioutil.ReadAll(journeyLocalVarFile)

openapi-generator version

Manifest-Version: 1.0
mode: development
package: org.openapitools
implementation-version: 5.4.0
Build-Jdk-Spec: 1.8
Created-By: Maven Jar Plugin 3.2.0
url: https://github.com/openapitools/openapi-generator/modules/openapi
-generator-cli
Main-Class: org.openapitools.codegen.OpenAPIGenerator

OpenAPI declaration file content or url

post:
  tags:
    - User Journey
  description: xxx
  requestBody:
    content:
      multipart/form-data:
        schema:
          properties:
            journey:
              type: string
              description: file name
              format: binary
  responses:
    "200":
      $ref: ErrorResponse.yaml
    "401":
      $ref: Unauthorised.yaml

Generation Details

java -jar ../../openapi/openapi-generator-cli.jar generate
-i api/XX.yaml
-g go
--additional-properties useOneOfDiscriminatorLookup=true,isGoSubmodule=false,sourceFolder=.,packageName=models
-o ./$1/models
--generate-alias-as-model
--git-user-id pol=xx
--git-repo-id xx

Steps to reproduce

Generate code using above

Related issues/PRs

Suggest a fix

No repository files or tests are named. Start by running the provided OpenAPI Generator command with the multipart/form-data YAML, then inspect the generated Go request struct and execute function shown in the report. Done means the generated code no longer produces the reported gofmt and errcheck lint errors.