tty: Replace TTY_THROTTLED bit tests with tty_throttled()

Abstract TTY_THROTTLED bit tests with tty_throttled().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 5997b17..3c4d7c2 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -600,7 +600,7 @@
 
 	hvcs_try_write(hvcsd);
 
-	if (!tty || test_bit(TTY_THROTTLED, &tty->flags)) {
+	if (!tty || tty_throttled(tty)) {
 		hvcsd->todo_mask &= ~(HVCS_READ_MASK);
 		goto bail;
 	} else if (!(hvcsd->todo_mask & (HVCS_READ_MASK)))