drivers/w1/masters/omap_hdq.c: fix missing mutex unlock

This was found using a semantic patch, more info can be found at:
http://www.emn.fr/x-info/coccinelle/Signed-off-by: Stoyan Gaydarov <sgayda2@uiuc.edu>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/w1/masters/omap_hdq.c

@@ -687,6 +687,7 @@ static int omap_hdq_remove(struct platform_device *pdev)
 
 	if (hdq_data->hdq_usecount) {
 		dev_dbg(&pdev->dev, "removed when use count is not zero\n");
+		mutex_unlock(&hdq_data->hdq_mutex);
 		return -EBUSY;
 	}