improve temp dirs handling an some logs

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/vfs/gcsfs.go

@@ -70,11 +70,7 @@ func init() {
 // NewGCSFs returns an GCSFs object that allows to interact with Google Cloud Storage
 func NewGCSFs(connectionID, localTempDir, mountPath string, config GCSFsConfig) (Fs, error) {
 	if localTempDir == "" {
-		if tempPath != "" {
-			localTempDir = tempPath
-		} else {
-			localTempDir = filepath.Clean(os.TempDir())
-		}
+		localTempDir = getLocalTempDir()
 	}
 
 	var err error