staging: nvec: implement unregistering of notifiers

This implements the unregistering of notifiers so kernel modules
can be unloaded.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/nvec/nvec.c

@@ -123,6 +123,20 @@ int nvec_register_notifier(struct nvec_chip *nvec, struct notifier_block *nb,
 }
 EXPORT_SYMBOL_GPL(nvec_register_notifier);
 
+/**
+ * nvec_unregister_notifier - Unregister a notifier with nvec
+ * @nvec: A &struct nvec_chip
+ * @nb: The notifier block to unregister
+ *
+ * Unregisters a notifier with @nvec. The notifier will be removed from the
+ * atomic notifier chain.
+ */
+int nvec_unregister_notifier(struct nvec_chip *nvec, struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&nvec->notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(nvec_unregister_notifier);
+
 /**
  * nvec_status_notifier - The final notifier
  *

drivers/staging/nvec/nvec.h

@@ -197,9 +197,8 @@ extern int nvec_register_notifier(struct nvec_chip *nvec,
 				  struct notifier_block *nb,
 				  unsigned int events);
 
-extern int nvec_unregister_notifier(struct device *dev,
-				    struct notifier_block *nb,
-				    unsigned int events);
+extern int nvec_unregister_notifier(struct nvec_chip *dev,
+				    struct notifier_block *nb);
 
 extern void nvec_msg_free(struct nvec_chip *nvec, struct nvec_msg *msg);