tty: tty_mutex.c: Fixed coding style warning (using printk)

Here I fixed from printk(KERN_ERR, ... to pr_err(... on tty_mutex.c

Signed-off-by: Sangho Yi <antiroot@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed