tty: Convert tty->closing to int

tty->closing is a bitfield member; prevent corruption from non-atomic
update by assigning a unique memory location.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/tty.h

@@ -284,7 +284,7 @@ struct tty_struct {
 
 #define N_TTY_BUF_SIZE 4096
 
-	unsigned char closing:1;
+	int closing;
 	unsigned char *write_buf;
 	int write_cnt;
 	/* If the tty has a pending do_SAK, queue it here - akpm */