[PATCH] git-cherry should show "+" instead of "-" and vice versa

In git-cherry.sh:

  if test -f "$patch/$2"
  then
    sign=-
  else
    sign=+
  fi

Documentation says 'If the change seems to be in the upstream, it is shown on
the standard output with prefix "+"', however the above does the reverse.  
When
the file $patch/$2 exists it is because the patch /is/ in upstream so the sign
should be "+".
Signed-off-by: Andy Parkins <andyparkins@gmail.com>
---
 git-cherry.sh |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)