git-codereview: update outdated error message

Replace the word "review" with os.Args[0] for consistency with change.go.

Change-Id: Id69d64e4275f4fdb39fc72e17ad3fb6daadd61da
Reviewed-on: https://go-review.googlesource.com/2303
Reviewed-by: Minux Ma <minux@golang.org>
1 file changed
tree: b6005262c771ef38fb9d02fc0a094e2200f38a8c
  1. .gitattributes
  2. README
  3. git-codereview/