USB: legousbtower: drop noisy disconnect messages

User space already sees -ENODEV in case it tries to do I/O post
disconnect, no need to spam the logs with printk messages that don't
even include any device-id information.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191105084152.16322-6-johan@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/legousbtower.c

@@ -540,7 +540,6 @@ static ssize_t tower_read (struct file *file, char __user *buffer, size_t count,
 	/* verify that the device wasn't unplugged */
 	if (dev->disconnected) {
 		retval = -ENODEV;
-		pr_err("No device or device unplugged %d\n", retval);
 		goto unlock_exit;
 	}
 
@@ -626,7 +625,6 @@ static ssize_t tower_write (struct file *file, const char __user *buffer, size_t
 	/* verify that the device wasn't unplugged */
 	if (dev->disconnected) {
 		retval = -ENODEV;
-		pr_err("No device or device unplugged %d\n", retval);
 		goto unlock_exit;
 	}