typo fix (#1293)

Summary:
fixes typo of the docstring.

Pull Request resolved: https://github.com/facebookresearch/pytorch3d/pull/1293

Differential Revision: D38737416

Pulled By: bottler

fbshipit-source-id: 3f9da3e97b55c2acd858263de9e85eaee272a98f

pytorch3d/ops/iou_box3d.py

@@ -115,7 +115,7 @@ def box3d_overlap(
     Computes the intersection of 3D boxes1 and boxes2.
 
     Inputs boxes1, boxes2 are tensors of shape (B, 8, 3)
-    (where B doesn't have to be the same for boxes1 and boxes1),
+    (where B doesn't have to be the same for boxes1 and boxes2),
     containing the 8 corners of the boxes, as follows:
 
         (4) +---------+. (5)