tty: Removing the deprecated function tty_vhangup_locked()

The function tty_vhangup_locked() was deprecated, removed it
from the tty.h also.
Signed-off-by: Liu, Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/tty.h

@@ -427,7 +427,6 @@ extern int is_ignored(int sig);
 extern int tty_signal(int sig, struct tty_struct *tty);
 extern void tty_hangup(struct tty_struct *tty);
 extern void tty_vhangup(struct tty_struct *tty);
-extern void tty_vhangup_locked(struct tty_struct *tty);
 extern void tty_unhangup(struct file *filp);
 extern int tty_hung_up_p(struct file *filp);
 extern void do_SAK(struct tty_struct *tty);