Fix nnictl view command

docs/en_US/Tutorial/Nnictl.md

@@ -128,6 +128,7 @@ Debug mode will disable version check function in Trialkeeper.
   |------|------|------ |------|
   |id|  True| |The id of the experiment you want to view|
   |--port, -p|  False| |Rest port of the experiment you want to view|
+  |--foreground, -f|False||set foreground mode, print log content to terminal|
 
 * Example
 

tools/nni_cmd/nnictl.py

@@ -63,10 +63,11 @@ def parse_args():
     parser_resume.set_defaults(func=resume_experiment)
 
     # parse view command
-    parser_resume = subparsers.add_parser('view', help='view a stopped experiment')
-    parser_resume.add_argument('id', nargs='?', help='The id of the experiment you want to view')
-    parser_resume.add_argument('--port', '-p', default=DEFAULT_REST_PORT, dest='port', help='the port of restful server')
-    parser_resume.set_defaults(func=view_experiment)
+    parser_view = subparsers.add_parser('view', help='view a stopped experiment')
+    parser_view.add_argument('id', nargs='?', help='The id of the experiment you want to view')
+    parser_view.add_argument('--port', '-p', default=DEFAULT_REST_PORT, dest='port', help='the port of restful server')
+    parser_view.add_argument('--foreground', '-f', action='store_true', help=' set foreground mode, print log content to terminal')
+    parser_view.set_defaults(func=view_experiment)
 
     # parse update command
     parser_updater = subparsers.add_parser('update', help='update the experiment')