USB: idmouse: drop redundant open-count check from release

The open count will always be exactly one when release is called, so
drop the redundant sanity check.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191105103638.4929-3-johan@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/idmouse.c

@@ -278,12 +278,6 @@ static int idmouse_release(struct inode *inode, struct file *file)
 	/* lock our device */
 	mutex_lock(&dev->lock);
 
-	/* are we really open? */
-	if (dev->open <= 0) {
-		mutex_unlock(&dev->lock);
-		return -ENODEV;
-	}
-
 	--dev->open;
 
 	if (!dev->present) {