TTY: get rid of BTM around devpts_*

devpts operations are protected by inode mutexes and dentry
refcounting. There is no need to hold BTM.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index ddec9f3..39afd04 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -54,8 +54,8 @@
 	wake_up_interruptible(&tty->link->write_wait);
 	if (tty->driver->subtype == PTY_TYPE_MASTER) {
 		set_bit(TTY_OTHER_CLOSED, &tty->flags);
-		devpts_pty_kill(tty->link);
 		tty_unlock();
+		devpts_pty_kill(tty->link);
 		tty_vhangup(tty->link);
 		tty_lock();
 	}
@@ -613,9 +613,7 @@
 		return retval;
 
 	/* find a device that is not in use. */
-	tty_lock();
 	index = devpts_new_index(inode);
-	tty_unlock();
 	if (index < 0) {
 		retval = index;
 		goto err_file;
@@ -650,8 +648,8 @@
 	tty_release(inode, filp);
 	return retval;
 out:
-	devpts_kill_index(inode, index);
 	tty_unlock();
+	devpts_kill_index(inode, index);
 err_file:
 	tty_free_file(filp);
 	return retval;
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 44736f9..ea7ebe2 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1789,11 +1789,11 @@
 	 * the slots and preserving the termios structure.
 	 */
 	release_tty(tty, idx);
+	tty_unlock();
 
 	/* Make this pty number available for reallocation */
 	if (devpts)
 		devpts_kill_index(inode, idx);
-	tty_unlock();
 	return 0;
 }