The header cleanup feature of this tool now removes empty ifdef's,
successive blank lines as well as moved option defines. So, we
want to see a little more context to check which lines were deleted.
It is true that we can see it by "git diff", but it would not work
in the --dry-run mode. So, here, this commit.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>