[Doc] Fix typo in dataloading.negative_sampler (#2177)

* fix dataloading docs

* fix another

docs/source/guide/minibatch-inference.rst

@@ -89,6 +89,8 @@ on how messages are aggregated and combined as well.
                     # Copy to output back to CPU.
                     y[output_nodes] = h.cpu()
 
+                x = y
+    
             return y
 
 Note that for the purpose of computing evaluation metric on the

python/dgl/dataloading/negative_sampler.py

@@ -48,7 +48,7 @@ class Uniform(_BaseNegativeSampler):
     Examples
     --------
     >>> g = dgl.graph(([0, 1, 2], [1, 2, 3]))
-    >>> neg_sampler = dgl.sampling.negative_sampler.Uniform(2)
+    >>> neg_sampler = dgl.dataloading.negative_sampler.Uniform(2)
     >>> neg_sampler(g, [0, 1])
     (tensor([0, 0, 1, 1]), tensor([1, 0, 2, 3]))
     """