fix unit test (#48624)

fix test_primapi

python/paddle/fluid/tests/unittests/autograd/test_primapi.py

@@ -677,16 +677,15 @@ where_wrap = lambda x, y: paddle.where(paddle.eye(3, 4) == 1, x, y)
             None,
             'float32',
         ),
-        ('var', paddle.var, (np.random.rand(200, 324),), None, 'float32'),
         (
-            'var_with_axis',
-            lambda x: paddle.var(x, axis=1),
-            (np.random.rand(10, 20, 30),),
+            'var',
+            lambda x: paddle.var(x, unbiased=False),
+            (np.random.rand(200, 324),),
             None,
             'float32',
         ),
         (
-            'var_without_unbiased',
+            'var_with_axis',
             lambda x: paddle.var(x, axis=1, unbiased=False),
             (np.random.rand(10, 20, 30),),
             None,
@@ -694,7 +693,7 @@ where_wrap = lambda x, y: paddle.where(paddle.eye(3, 4) == 1, x, y)
         ),
         (
             'var_with_keepdim',
-            lambda x: paddle.var(x, axis=1, keepdim=True),
+            lambda x: paddle.var(x, axis=1, keepdim=True, unbiased=False),
             (np.random.rand(10, 20, 30),),
             None,
             'float32',