* fhandler.h (fhandler_dev_zero::lseek): Convert to inline method.

(class fhandler_dev_random): Drop dummy_offset.
	(fhandler_dev_random::lseek): Convert to inline method.
	(fhandler_dev_dsp::lseek): Ditto.
	* fhandler_dsp.cc (fhandler_dev_dsp::lseek): Drop here.
	* fhandler_random.cc (fhandler_dev_random::open): Drop setting
	dummy_offset.
	(fhandler_dev_random::lseek): Drop here.
	* fhandler_tape.cc (fhandler_dev_tape::lseek): Make no-op, but keep
	old code for reference.
	* fhandler_zero.cc (fhandler_dev_zero::lseek): Drop here.

winsup/cygwin/fhandler_zero.cc

@@ -37,9 +37,3 @@ fhandler_dev_zero::read (void *ptr, size_t& len)
 {
   memset (ptr, 0, len);
 }
-
-off_t
-fhandler_dev_zero::lseek (off_t, int)
-{
-  return 0;
-}