drm: Update docs around gem_free_object

Not all places correctly stated that gem_free_object_unlocked is the
one to use.

Reported-by: Eric Anholt <eric@anholt.net
Cc: Eric Anholt <eric@anholt.net
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170718063337.31942-1-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Documentation/gpu/drm-mm.rst

@@ -191,7 +191,7 @@ acquired and release by :c:func:`calling drm_gem_object_get()` and
 holding the lock.
 
 When the last reference to a GEM object is released the GEM core calls
-the :c:type:`struct drm_driver <drm_driver>` gem_free_object
+the :c:type:`struct drm_driver <drm_driver>` gem_free_object_unlocked
 operation. That operation is mandatory for GEM-enabled drivers and must
 free the GEM object and all associated resources.
 

drivers/gpu/drm/drm_gem_cma_helper.c

@@ -177,7 +177,7 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv,
  * This function frees the backing memory of the CMA GEM object, cleans up the
  * GEM object state and frees the memory used to store the object itself.
  * Drivers using the CMA helpers should set this as their
- * &drm_driver.gem_free_object callback.
+ * &drm_driver.gem_free_object_unlocked callback.
  */
 void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
 {