Cleanup: remove duplicate doc-strings

Internal struct ObTfmBack had out of sync doc-strings
for members duplicated from Object.

Remove the doc-strings as there is this is just temporary storage.

source/blender/blenkernel/intern/object.cc

@@ -4342,28 +4342,18 @@ void BKE_scene_foreach_display_point(Depsgraph *depsgraph,
 }
 
 /**
- * Struct members from DNA_object_types.h
+ * See struct members from #Object in DNA_object_types.h
  */
 struct ObTfmBack {
   float loc[3], dloc[3];
-  /** scale and delta scale. */
   float scale[3], dscale[3];
-  /** euler rotation. */
   float rot[3], drot[3];
-  /** quaternion rotation. */
   float quat[4], dquat[4];
-  /** axis angle rotation - axis part. */
   float rotAxis[3], drotAxis[3];
-  /** axis angle rotation - angle part. */
   float rotAngle, drotAngle;
-  /** final worldspace matrix with constraints & animsys applied. */
   float obmat[4][4];
-  /** inverse result of parent, so that object doesn't 'stick' to parent. */
   float parentinv[4][4];
-  /** inverse result of constraints. doesn't include effect of parent or object local transform.
-   */
   float constinv[4][4];
-  /** inverse matrix of 'obmat' for during render, temporally: ipokeys of transform. */
   float imat[4][4];
 };