fix warning for enable_graph_kernel context in CPU device

mindspore/nn/optim/lamb.py

@@ -277,8 +277,8 @@ class Lamb(Optimizer):
             self.global_step = Parameter(initializer(0, [1]), name='global_step')
             self.assignadd = P.AssignAdd()
         self.hyper_map = C.HyperMap()
-        self.enable_graph_kernel = context.get_context("enable_graph_kernel") and \
-            context.get_context("device_target") == "Ascend"
+        self.enable_graph_kernel = context.get_context("device_target") == "Ascend" and \
+            context.get_context("enable_graph_kernel")
 
     def construct(self, gradients):
         lr = self.get_lr()

mindspore/ops/op_selector.py

@@ -56,7 +56,7 @@ class _OpSelector:
 
     def __call__(self, *args, **kwargs):
         _op_type = _OpSelector.DEFAULT_OP_TYPE
-        if context.get_context("enable_graph_kernel"):
+        if context.get_context("device_target") in ['Ascend', 'GPU'] and context.get_context("enable_graph_kernel"):
             if _OpSelector.KW_STR in kwargs:
                 _op_type = kwargs.get(_OpSelector.KW_STR)
                 kwargs.pop(_OpSelector.KW_STR, None)