Fix typo in code documentation (#2314)

slim/nets/mobilenet_v1.py

@@ -154,7 +154,7 @@ def mobilenet_v1_base(inputs,
     inputs: a tensor of shape [batch_size, height, width, channels].
     final_endpoint: specifies the endpoint to construct the network up to. It
       can be one of ['Conv2d_0', 'Conv2d_1_pointwise', 'Conv2d_2_pointwise',
-      'Conv2d_3_pointwise', 'Conv2d_4_pointwise', 'Conv2d_5'_pointwise,
+      'Conv2d_3_pointwise', 'Conv2d_4_pointwise', 'Conv2d_5_pointwise',
       'Conv2d_6_pointwise', 'Conv2d_7_pointwise', 'Conv2d_8_pointwise',
       'Conv2d_9_pointwise', 'Conv2d_10_pointwise', 'Conv2d_11_pointwise',
       'Conv2d_12_pointwise', 'Conv2d_13_pointwise'].