driver core: remove polling for driver_probe_done(v5)

This patch removes 100ms polling for driver_probe_done in
wait_for_device_probe(), and uses wait_event() instead.
Removing polling in fs initialization may lead to
a faster boot.

This patch also changes the return type of wait_for_device_done()
from int to void.

This patch is against Arjan's patch in linux-next tree.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/device.h b/include/linux/device.h
index d5706c4..c56b154 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -147,7 +147,7 @@
 extern struct device_driver *driver_find(const char *name,
 					 struct bus_type *bus);
 extern int driver_probe_done(void);
-extern int wait_for_device_probe(void);
+extern void wait_for_device_probe(void);
 
 
 /* sysfs interface for exporting driver attributes */