TTY: remove minor_num from tty_driver

It was added back in 2004 and never used for anything real. Remove the
only assignment in the tree as well.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/pti.c

@@ -920,7 +920,6 @@ static int __init pti_init(void)
 	pti_tty_driver->name			= TTYNAME;
 	pti_tty_driver->major			= 0;
 	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
-	pti_tty_driver->minor_num		= PTITTY_MINOR_NUM;
 	pti_tty_driver->num			= PTITTY_MINOR_NUM;
 	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
 	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;

include/linux/tty_driver.h

@@ -299,7 +299,6 @@ struct tty_driver {
 	int	name_base;	/* offset of printed name */
 	int	major;		/* major device number */
 	int	minor_start;	/* start of minor device number */
-	int	minor_num;	/* number of *possible* devices */
 	int	num;		/* number of devices allocated */
 	short	type;		/* type of tty driver */
 	short	subtype;	/* subtype of tty driver */