serial: mux: constify uart_ops structures

These uart_ops structures are only stored in the ops field of a
uart_port structure and this fields is const, so the uart_ops
structures can also be const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/mux.c

@@ -427,7 +427,7 @@ static struct console mux_console = {
 #define MUX_CONSOLE	NULL
 #endif
 
-static struct uart_ops mux_pops = {
+static const struct uart_ops mux_pops = {
 	.tx_empty =		mux_tx_empty,
 	.set_mctrl =		mux_set_mctrl,
 	.get_mctrl =		mux_get_mctrl,