cleanup: All conditionals simplified under pkg. (#3875)

Address all the changes reported/recommended by
`gosimple` tool.

pkg/disk/type_linux.go

@@ -40,7 +40,7 @@ var fsType2StringMap = map[string]string{
 func getFSType(ftype int64) string {
 	fsTypeHex := strconv.FormatInt(ftype, 16)
 	fsTypeString, ok := fsType2StringMap[fsTypeHex]
-	if ok == false {
+	if !ok {
 		return "UNKNOWN"
 	}
 	return fsTypeString

pkg/madmin/api.go

@@ -1,5 +1,5 @@
 /*
- * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ * Minio Cloud Storage, (C) 2016, 2017 Minio, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -276,12 +276,7 @@ func (c AdminClient) dumpHTTP(req *http.Request, resp *http.Response) error {
 
 	// Ends the http dump.
 	_, err = fmt.Fprintln(c.traceOutput, "---------END-HTTP---------")
-	if err != nil {
-		return err
-	}
-
-	// Returns success.
-	return nil
+	return err
 }
 
 // do - execute http request.

pkg/madmin/heal-commands.go

@@ -211,10 +211,7 @@ func (adm *AdminClient) listObjectsHeal(bucket, prefix, marker, delimiter string
 	}
 
 	err = xml.NewDecoder(resp.Body).Decode(&toBeHealedObjects)
-	if err != nil {
-		return toBeHealedObjects, err
-	}
-	return toBeHealedObjects, nil
+	return toBeHealedObjects, err
 }
 
 // ListObjectsHeal - Lists upto maxKeys objects that needing heal matching bucket, prefix, marker, delimiter.

pkg/mimedb/db_test.go

@@ -1,5 +1,5 @@
 /*
- * mime-db: Mime Database, (C) 2015, 2016 Minio, Inc.
+ * mime-db: Mime Database, (C) 2015, 2016, 2017 Minio, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,7 @@ func TestMimeLookup(t *testing.T) {
 		t.Fatalf("Invalid content type are found expected \"application/x-msdownload\", got %s", contentType)
 	}
 	compressible := DB["txt"].Compressible
-	if compressible != false {
+	if compressible {
 		t.Fatalf("Invalid content type are found expected \"false\", got %t", compressible)
 	}
 }

pkg/quick/encoding.go

@@ -122,8 +122,7 @@ func saveFileConfig(filename string, v interface{}) error {
 // decoder format according to the filename extension. If no
 // extension is provided, json will be selected by default.
 func loadFileConfig(filename string, v interface{}) error {
-	_, err := os.Stat(filename)
-	if err != nil {
+	if _, err := os.Stat(filename); err != nil {
 		return err
 	}
 	fileData, err := ioutil.ReadFile(filename)
@@ -133,10 +132,6 @@ func loadFileConfig(filename string, v interface{}) error {
 	if runtime.GOOS == "windows" {
 		fileData = []byte(strings.Replace(string(fileData), "\r\n", "\n", -1))
 	}
-	ext := filepath.Ext(filename)
 	// Unmarshal file's content
-	if err := toUnmarshaller(ext)(fileData, v); err != nil {
-		return err
-	}
-	return nil
+	return toUnmarshaller(filepath.Ext(filename))(fileData, v)
 }