Comma-separated failure codes reusing the description

[josephzidell]

Describe the bug
Comma-separated failure codes reusing the description

To Reproduce
Steps to reproduce the behavior:

// @Failure 400,404 {object} response.Response

generates

"400": {
	"description": "Bad Request",
	"schema": {
		"$ref": "#/definitions/response.Response"
	}
},
"404": {
	"description": "Bad Request", // <-- 1.7.0 generates incorrect status description
	"schema": {
		"$ref": "#/definitions/response.Response"
	}
}

Expected behavior

"400": {
	"description": "Bad Request",
	"schema": {
		"$ref": "#/definitions/response.Response"
	}
},
"404": {
	"description": "Not Found", // <-- in 1.6.9, when they were on separate lines, generated correct status description
	"schema": {
		"$ref": "#/definitions/response.Response"
	}
}

Screenshots
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Your swag version
e.g. 1.7.0

Your go version
e.g. 1.15.5

Desktop (please complete the following information):

• OS: Mac
• Browser: Firefox
• Version: latest

Additional context
Add any other context about the problem here.