TTY: move ldisc data from tty_struct: locks

atomic_write_lock is not n_tty specific, so move it up in the
tty_struct.

And since these are the last ones to move, remove also the comment
saying there are some ldisc' members. There are none now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 226cf20..08787ec 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -235,6 +235,7 @@
 	struct mutex ldisc_mutex;
 	struct tty_ldisc *ldisc;
 
+	struct mutex atomic_write_lock;
 	struct mutex legacy_mutex;
 	struct mutex termios_mutex;
 	spinlock_t ctrl_lock;
@@ -265,20 +266,10 @@
 
 #define N_TTY_BUF_SIZE 4096
 
-	/*
-	 * The following is data for the N_TTY line discipline.  For
-	 * historical reasons, this is included in the tty structure.
-	 * Mostly locked by the BKL.
-	 */
 	unsigned char closing:1;
 	unsigned short minimum_to_wake;
-	struct mutex atomic_read_lock;
-	struct mutex atomic_write_lock;
-	struct mutex output_lock;
-	struct mutex echo_lock;
 	unsigned char *write_buf;
 	int write_cnt;
-	spinlock_t read_lock;
 	/* If the tty has a pending do_SAK, queue it here - akpm */
 	struct work_struct SAK_work;
 	struct tty_port *port;