refine code

Author: zenghsh3

python/paddle/fluid/tests/unittests/test_sampling_id_op.py

@@ -27,7 +27,7 @@ def setUp(self):
         self.init_kernel_type()
         self.X = np.random.random((100, 10)).astype('float32')
         self.inputs = {"X": self.X}
-        self.Y = np.random.random(100).astype('float32')
+        self.Y = np.random.random(100).astype('int64')
         self.outputs = {'Out': self.Y}
         self.attrs = {'max': 1.0, 'min': 0.0, 'seed': 1}