Fix test_grid_sample.py and test_affine_grid.py threshold

[tingkuanpei]

修复 test_grid_sample.py 和 test_affine_grid.py 阈值过低导致test有概率失败的问题

[github-actions]

Speed stats:

GPU Name: GeForce GTX 1080 

OneFlow resnet50 time: 128.3ms (= 6415.4ms / 50, input_shape=[16, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 142.1ms (= 7104.6ms / 50, input_shape=[16, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.11 (= 142.1ms / 128.3ms)

OneFlow resnet50 time: 74.5ms (= 3725.9ms / 50, input_shape=[8, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 82.3ms (= 4114.9ms / 50, input_shape=[8, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.10 (= 82.3ms / 74.5ms)

OneFlow resnet50 time: 47.4ms (= 2368.3ms / 50, input_shape=[4, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 60.0ms (= 3000.4ms / 50, input_shape=[4, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.27 (= 60.0ms / 47.4ms)

OneFlow resnet50 time: 41.6ms (= 2082.1ms / 50, input_shape=[2, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 47.9ms (= 2395.2ms / 50, input_shape=[2, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.15 (= 47.9ms / 41.6ms)

OneFlow resnet50 time: 41.5ms (= 2077.3ms / 50, input_shape=[1, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 43.7ms (= 2185.6ms / 50, input_shape=[1, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.05 (= 43.7ms / 41.5ms)

OneFlow resnet50 time: 135.7ms (= 6787.4ms / 50, input_shape=[16, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 146.4ms (= 7322.3ms / 50, input_shape=[16, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.08 (= 146.4ms / 135.7ms)

OneFlow resnet50 time: 84.4ms (= 4220.7ms / 50, input_shape=[8, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 93.9ms (= 4692.8ms / 50, input_shape=[8, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.11 (= 93.9ms / 84.4ms)

OneFlow resnet50 time: 62.5ms (= 3125.6ms / 50, input_shape=[4, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 65.4ms (= 3270.8ms / 50, input_shape=[4, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 1.05 (= 65.4ms / 62.5ms)

OneFlow resnet50 time: 59.0ms (= 2949.6ms / 50, input_shape=[2, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 54.9ms (= 2743.5ms / 50, input_shape=[2, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 0.93 (= 54.9ms / 59.0ms)

OneFlow resnet50 time: 59.0ms (= 2950.1ms / 50, input_shape=[1, 3, 224, 224], backward is enabled)
OneFlow GPU used (rank 0): 0 MiB
PyTorch resnet50 time: 48.5ms (= 2422.7ms / 50, input_shape=[1, 3, 224, 224], backward is enabled)
PyTorch GPU used (rank 0, estimated): 0 MiB
Relative speed: 0.82 (= 48.5ms / 59.0ms)