driver core: Add missing annotation for device_links_read_lock()

Sparse reports a warning at device_links_read_unlock()

warning:  warning: context imbalance in device_links_read_unlock()
	 - unexpected unlock

The root cause is the missing annotation at device_links_read_unlock()
Add the missing __releases(&device_links_srcu) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Link: https://lore.kernel.org/r/20200214204741.94112-20-jbi.octave@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/core.c

@@ -69,7 +69,7 @@ int device_links_read_lock(void)
 	return srcu_read_lock(&device_links_srcu);
 }
 
-void device_links_read_unlock(int idx)
+void device_links_read_unlock(int idx) __releases(&device_links_srcu)
 {
 	srcu_read_unlock(&device_links_srcu, idx);
 }