serial: kill USF_CLOSING_* definitions

The serial layer for some reason uses different defines for the special
case close delays and then conditionally switches to/from the normal ones
in the ioctls.

Remove this rather pointless abstraction

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/serial_core.h

@@ -342,9 +342,6 @@ struct uart_port {
 struct uart_state {
 	struct tty_port		port;
 
-#define USF_CLOSING_WAIT_INF	(0)
-#define USF_CLOSING_WAIT_NONE	(~0U)
-
 	int			pm_state;
 	struct circ_buf		xmit;