checkpatch: add ability to insert and delete lines to patch/file

This can be valuable to insert or delete blank lines as well as fix
misplaced brace or else uses.

Store indexes of lines to be added/deleted and the new lines.

When creating the --fix file, insert or delete the appropriate lines and
update the patch range information.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>