gooftool: avoid using --add-file option of tar

There is a bug in tar command that --add-file is not working now:
https://lists.libreplanet.org/archive/html/bug-tar/2016-11/msg00013.html

remove --add-file options in gooftool.

BUG=None
TEST=manual

Change-Id: I2b12da01a4ab705c9669443d20306a1850d390b3
Reviewed-on: https://chromium-review.googlesource.com/424518
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
diff --git a/py/gooftool/commands.py b/py/gooftool/commands.py
index 1a77672..0e3c125 100755
--- a/py/gooftool/commands.py
+++ b/py/gooftool/commands.py
@@ -598,7 +598,7 @@
 
   # Intentionally ignoring dotfiles in EVENT_LOG_DIR.
   tar_cmd = 'cd %s ; tar cJf %s *' % (event_log.EVENT_LOG_DIR, target_path)
-  tar_cmd += ' --add-file %s' % paths.GetFactoryLogPath()
+  tar_cmd += ' %s' % paths.GetFactoryLogPath()
   if add_file:
     for f in add_file:
       # Require absolute paths since the tar command may change the
@@ -607,7 +607,7 @@
         raise Error('Not an absolute path: %s' % f)
       if not os.path.exists(f):
         raise Error('File does not exist: %s' % f)
-      tar_cmd += ' --add-file %s' % pipes.quote(f)
+      tar_cmd += ' %s' % pipes.quote(f)
   cmd_result = Shell(tar_cmd)
 
   if ((cmd_result.status == 1) and