Correct the dropout_op's computation in test

paddle/operators/dropout_op.cu

@@ -71,7 +71,7 @@ class GPUDropoutKernel : public framework::OpKernel<T> {
       auto M = EigenMatrix<T>::Reshape(*mask, 1);
       Y.device(place) = X * M;
     } else {
-      Y.device(place) = X * dropout_prob;
+      Y.device(place) = X * (1.0f - dropout_prob);
     }
   }
 };

paddle/operators/dropout_op.h

@@ -57,7 +57,7 @@ class CPUDropoutKernel : public framework::OpKernel<T> {
       auto Y = EigenMatrix<T>::Reshape(*y, 1);
       auto& place =
           *context.template device_context<DeviceContext>().eigen_device();
-      Y.device(place) = X * dropout_prob;
+      Y.device(place) = X * (1.0f - dropout_prob);
     }
   }
 };

python/paddle/v2/fluid/tests/test_dropout_op.py

@@ -47,7 +47,9 @@ class TestDropoutOp4(OpTest):
         self.op_type = "dropout"
         self.inputs = {'X': np.random.random((32, 64)).astype("float32")}
         self.attrs = {'dropout_prob': 0.35, 'is_test': True}
-        self.outputs = {'Out': self.inputs['X'] * self.attrs['dropout_prob']}
+        self.outputs = {
+            'Out': self.inputs['X'] * (1.0 - self.attrs['dropout_prob'])
+        }
 
     def test_check_output(self):
         self.check_output()
@@ -58,7 +60,9 @@ class TestDropoutOp5(OpTest):
         self.op_type = "dropout"
         self.inputs = {'X': np.random.random((32, 64, 3)).astype("float32")}
         self.attrs = {'dropout_prob': 0.75, 'is_test': True}
-        self.outputs = {'Out': self.inputs['X'] * self.attrs['dropout_prob']}
+        self.outputs = {
+            'Out': self.inputs['X'] * (1.0 - self.attrs['dropout_prob'])
+        }
 
     def test_check_output(self):
         self.check_output()