[PATCH] const struct tty_operations

As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking.  One of these
structures was a struct tty_operations.  In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.

This patch declares all struct tty_operations in the tree as const.  In all
cases, they are static and used only as input to tty_set_operations.  As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.

53 drivers are affected.  I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months.  serial_core.c was the busiest one that I looked at.

Signed-off-by: Jeff Dike <[email protected]>
Acked-by: Alan Cox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/xtensa/platform-iss/console.c

@@ -191,7 +191,7 @@ static int rs_read_proc(char *page, char **start, off_t off, int count,
 }
 
 
-static struct tty_operations serial_ops = {
+static const struct tty_operations serial_ops = {
 	.open = rs_open,
 	.close = rs_close,
 	.write = rs_write,