fix wrong order of hidden and cell state (fix microsoft#2839)

src/sdk/pynni/nni/nas/pytorch/enas/mutator.py

@@ -17,16 +17,16 @@ def __init__(self, layers, size, bias):
                                            for _ in range(self.lstm_num_layers)])
 
     def forward(self, inputs, hidden):
-        prev_c, prev_h = hidden
-        next_c, next_h = [], []
+        prev_h, prev_c = hidden
+        next_h, next_c = [], []
         for i, m in enumerate(self.lstm_modules):
-            curr_c, curr_h = m(inputs, (prev_c[i], prev_h[i]))
+            curr_h, curr_c = m(inputs, (prev_h[i], prev_c[i]))
             next_c.append(curr_c)
             next_h.append(curr_h)
             # current implementation only supports batch size equals 1,
             # but the algorithm does not necessarily have this limitation
             inputs = curr_h[-1].view(1, -1)
-        return next_c, next_h
+        return next_h, next_c
 
 
 class EnasMutator(Mutator):
@@ -136,7 +136,7 @@ def _initialize(self):
         self.sample_skip_penalty = 0
 
     def _lstm_next_step(self):
-        self._c, self._h = self.lstm(self._inputs, (self._c, self._h))
+        self._h, self._c = self.lstm(self._inputs, (self._h, self._c))
 
     def _mark_anchor(self, key):
         self._anchors_hid[key] = self._h[-1]