!15865 fix fasterrcnn fail in pynative

From: @chujinjin
Reviewed-by: @linqingke,@kisnwang
Signed-off-by: @linqingke

mindspore/ops/operations/array_ops.py

@@ -311,14 +311,16 @@ class Cast(PrimitiveWithInfer):
 
     def check_elim(self, x, dtype):
         if isinstance(x, (Tensor, numbers.Number, Parameter)):
-            if isinstance(x, Tensor) and x.dtype == dtype:
-                return (True, x)
-            if isinstance(x, numbers.Number):
-                return (True, Tensor(x, dtype=dtype))
             if isinstance(x, Parameter):
                 data = x.data
                 if data.dtype == dtype:
                     return (True, x)
+            if isinstance(x, Tensor) and x.dtype == dtype:
+                x = Tensor(x)
+                x.set_cast_dtype()
+                return (True, x)
+            if isinstance(x, numbers.Number):
+                return (True, Tensor(x, dtype=dtype))
         return (False, None)
 
     def __infer__(self, x, t):

model_zoo/official/cv/faster_rcnn/src/FasterRcnn/rcnn.py

@@ -143,7 +143,7 @@ class Rcnn(nn.Cell):
 
         if self.training:
             bbox_weights = self.cast(self.logicaland(self.greater(labels, 0), mask), mstype.int32) * labels
-            labels = self.cast(self.onehot(labels, self.num_classes, self.on_value, self.off_value), self.ms_type)
+            labels = self.onehot(labels, self.num_classes, self.on_value, self.off_value)
             bbox_targets = self.tile(self.expandims(bbox_targets, 1), (1, self.num_classes, 1))
 
             loss, loss_cls, loss_reg, loss_print = self.loss(x_cls, x_reg, bbox_targets, bbox_weights, labels, mask)