HID: hidraw: fix improper mutex release

Mutex can not be released unless all hid_device members are properly
initialized. Otherwise it would result in a race condition that can
cause NULL pointer kernel panic issue in hidraw_open where it uses
uninitialized 'list' member in list_add_tail().

Signed-off-by: Yonghua Zheng <younghua.zheng@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index a745163..6f1feb2 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -518,7 +518,6 @@
 		goto out;
 	}
 
-	mutex_unlock(&minors_lock);
 	init_waitqueue_head(&dev->wait);
 	INIT_LIST_HEAD(&dev->list);
 
@@ -528,6 +527,7 @@
 	dev->exist = 1;
 	hid->hidraw = dev;
 
+	mutex_unlock(&minors_lock);
 out:
 	return result;