drm/gem: Fix typo in kerneldoc

The function being documented is drm_gem_object_handle_free(), not
drm_gem_object_free().

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index f6ca512..973a9b6 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -188,7 +188,7 @@
 }
 
 /**
- * drm_gem_object_free - release resources bound to userspace handles
+ * drm_gem_object_handle_free - release resources bound to userspace handles
  * @obj: GEM object to clean up.
  *
  * Called after the last handle to the object has been closed