Fix formatting error in docs.

Signed-off-by: Edward Z. Yang <ezyang@fb.com>

Author: ezyang

docs/source/sparse.rst

@@ -21,7 +21,6 @@ by providing these two tensors, as well as the size of the sparse tensor
  >>> i = torch.LongTensor([[0, 1], [2, 0]])
  >>> v = torch.FloatTensor([3, 4])
  >>> torch.sparse.FloatTensor(i, v, torch.Size([2,3])).to_dense()
-
  0 0 3
  4 0 0
  [torch.FloatTensor of size 2x2]
@@ -32,7 +31,6 @@ dimensions are sparse, and the rest of the dimensions are dense.
  >>> i = torch.LongTensor([[2, 4]])
  >>> v = torch.FloatTensor([[1, 3], [5, 7]])
  >>> torch.sparse.FloatTensor(i, v).to_dense()
-
  0 0
  0 0
  1 3