watchdog: ts72xx_wdt: locking bug in ioctl

commit 8612ed0d upstream.

Calling the WDIOC_GETSTATUS & WDIOC_GETBOOTSTATUS and twice will cause a
interruptible deadlock.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/watchdog/ts72xx_wdt.c

@@ -310,7 +310,8 @@ static long ts72xx_wdt_ioctl(struct file *file, unsigned int cmd,
 
 	case WDIOC_GETSTATUS:
 	case WDIOC_GETBOOTSTATUS:
-		return put_user(0, p);
+		error = put_user(0, p);
+		break;
 
 	case WDIOC_KEEPALIVE:
 		ts72xx_wdt_kick(wdt);