driver core: Add missing annotation for device_links_write_lock()

Sparse reports a warning at device_links_write_lock()

warning: context imbalance in evice_links_write_lock()
	 - wrong count at exit

The root cause is the missing annotation at device_links_write_lock()
Add the missing __acquires(&device_links_srcu) annotation
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Link: https://lore.kernel.org/r/20200214204741.94112-19-jbi.octave@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/core.c

@@ -64,7 +64,7 @@ static inline void device_links_write_unlock(void)
 	mutex_unlock(&device_links_lock);
 }
 
-int device_links_read_lock(void)
+int device_links_read_lock(void) __acquires(&device_links_srcu)
 {
 	return srcu_read_lock(&device_links_srcu);
 }