fix doc for as_tensor (pytorch#10309)

Summary:
- fixes pytorch#9914
Pull Request resolved: pytorch#10309

Differential Revision: D9196427

Pulled By: weiyangfb

fbshipit-source-id: c9a01e42c2e9dbfe2bd94ad14651d9f578751de2

Author: weiyangfb

torch/_torch_docs.py

@@ -425,18 +425,21 @@ def parse_kwargs(desc):
 
 Example::
 
-    >>> torch.tensor([[0.1, 1.2], [2.2, 3.1], [4.9, 5.2]])
-    tensor([[ 0.1000,  1.2000],
-            [ 2.2000,  3.1000],
-            [ 4.9000,  5.2000]])
-
     >>> a = numpy.array([1, 2, 3])
-    >>> t = torch.from_numpy(a)
+    >>> t = torch.as_tensor(a)
     >>> t
     tensor([ 1,  2,  3])
     >>> t[0] = -1
     >>> a
     array([-1,  2,  3])
+
+    >>> a = numpy.array([1, 2, 3])
+    >>> t = torch.as_tensor(a, device=torch.device('cuda'))
+    >>> t
+    tensor([ 1,  2,  3])
+    >>> t[0] = -1
+    >>> a
+    array([1,  2,  3])
 """.format(**factory_data_common_args))
 
 add_docstr(torch.asin,