fix Profiler api comment format bug

mindinsight/profiler/README.md

@@ -20,7 +20,7 @@ To enable profiling on MindSpore, the MindInsight Profiler apis should be added
     Example:
         
         context.set_context(mode=context.GRAPH_MODE, device_target="Ascend", device_id=int(os.environ["DEVICE_ID"]))
-        profiler = Profiler(output_path="./data", is_detail=True, is_show_op_path=False, subgraph='All')
+        profiler = Profiler(output_path="./data", is_detail=True, is_show_op_path=False, subgraph='all')
         net = Net()
         
     Parameters of Profiler including：

mindinsight/profiler/profiling.py

@@ -50,7 +50,7 @@ class Profiler:
 
     Examples:
         >>> from mindinsight.profiler import Profiler
-        >>> context.set_context(mode=context.GRAPH_MODE, device_target=“Ascend”,
+        >>> context.set_context(mode=context.GRAPH_MODE, device_target="Ascend",
         >>>                     device_id=int(os.environ["DEVICE_ID"]))
         >>> profiler = Profiler(subgraph='all', is_detail=True, is_show_op_path=False, output_path='./data')
         >>> model = Model(train_network)
@@ -128,7 +128,7 @@ class Profiler:
 
         Examples:
             >>> from mindinsight.profiler import Profiler
-            >>> context.set_context(mode=context.GRAPH_MODE, device_target=“Ascend”,
+            >>> context.set_context(mode=context.GRAPH_MODE, device_target="Ascend",
             >>>                     device_id=int(os.environ["DEVICE_ID"]))
             >>> profiler = Profiler(subgraph='all', is_detail=True, is_show_op_path=False, output_path='./data')
             >>> model = Model(train_network)