tty: Replace TTY_IO_ERROR bit tests with tty_io_error()

Abstract TTY_IO_ERROR status test treewide with tty_io_error().
NB: tty->flags uses atomic bit ops; replace non-atomic bit test
with test_bit().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -1070,7 +1070,7 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
 
 	if (tty_paranoia_check(tty, inode, "tty_read"))
 		return -EIO;
-	if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
+	if (!tty || tty_io_error(tty))
 		return -EIO;
 
 	/* We want to wait for the line discipline to sort out in this
@@ -1245,8 +1245,7 @@ static ssize_t tty_write(struct file *file, const char __user *buf,
 
 	if (tty_paranoia_check(tty, file_inode(file), "tty_write"))
 		return -EIO;
-	if (!tty || !tty->ops->write ||
-		(test_bit(TTY_IO_ERROR, &tty->flags)))
+	if (!tty || !tty->ops->write ||	tty_io_error(tty))
 			return -EIO;
 	/* Short term debug to catch buggy drivers */
 	if (tty->ops->write_room == NULL)