mtd: partitions: kill unused ecclayout struct

This field is not used.

Reported here:

http://lists.infradead.org/pipermail/linux-mtd/2015-October/062417.html



Reported-by: Brian Foster <brian.foster@maximintegrated.com>
Cc: Brian Foster <brian.foster@maximintegrated.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>