Revert "fromupstream: use --reject for git-apply"

This reverts commit 3a4ebdaa6e0d7aefdc25765d473e09979c554bc3.

When trying to apply a patch that cleanly applies, I'm now getting
errors.  Removing the "--reject" flag fixes it.  Example:

 fromupstream.py -b=b:161373813 -t="None" pw://lkml/1293172

As per git documentation, "--reject" is incompatible with "-3" and
I think we want "-3" more (if nothing else because that's what we've
historically had).  If someone needs "--reject" I suppose we could
add another option...

BUG=None
TEST=fromupstream.py -b=b:161373813 -t="None" pw://lkml/1293172

Change-Id: I8261da243b145d2993ca53a813b3216d837ad5ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2369145
Commit-Queue: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
diff --git a/contrib/fromupstream.py b/contrib/fromupstream.py
index 832eaec..cab538a 100755
--- a/contrib/fromupstream.py
+++ b/contrib/fromupstream.py
@@ -231,8 +231,7 @@
     if args['replace']:
         _git(['reset', '--hard', 'HEAD~1'])
 
-    return _git_returncode(['am', '-3', '--reject'], stdin=patch_contents,
-                           encoding=None)
+    return _git_returncode(['am', '-3'], stdin=patch_contents, encoding=None)
 
 def _match_patchwork(match, args):
     """Match location: pw://### or pw://PROJECT/###."""