mei: bus: fix notification event delivery

Call wake_up cl->ev_wait only in case there is no bus client registered
to the event notification.
Second, since we don't have exclusive waiter wake_up_interruptible_all
is not used correctly here.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/mei_dev.h

@@ -317,7 +317,7 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
 			bool blocking);
 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length);
 bool mei_cl_bus_rx_event(struct mei_cl *cl);
-void mei_cl_bus_notify_event(struct mei_cl *cl);
+bool mei_cl_bus_notify_event(struct mei_cl *cl);
 void mei_cl_bus_remove_devices(struct mei_device *bus);
 int mei_cl_bus_init(void);
 void mei_cl_bus_exit(void);