Skip exp float16 test in XNNPACk

Author: mergennachin

backends/xnnpack/test/ops/test_exp.py

@@ -22,7 +22,7 @@ def forward(self, x):
             return torch.exp(x)
 
     def run_exp_test(self, inputs):
-        (
+        return (
             Tester(self.Exp(), inputs)
             .export()
             .check_count({"torch.ops.aten.exp.default": 1})
@@ -34,6 +34,9 @@ def run_exp_test(self, inputs):
             .run_method_and_compare_outputs()
         )
 
+    # TODO (leafs1): Fix flaky tests. Land fix asap 
+    # and cherry-pick onto release/0.7 branch
+    @unittest.skip(reason="For float16, numerical discepancies are too high")
     def test_fp16_exp(self):
         inputs = (torch.randn(20).to(torch.float16),)
         self.run_exp_test(inputs)