(fs) Needless instanceof check in RegistryFileTypeDetector

Type of file parameter is known to be Path. And instanceof only checks if it's null or not.

 public String implProbeContentType(Path file) throws IOException {
     if (!(file instanceof Path))
         return null;

Before implProbeContentType method is called, parameter is checked for null in sun.nio.fs.AbstractFileTypeDetector#probeContentType. It means null check is redundant too.