Preserving images for every partition doubles disk space
consumed by an image build. As those images are not used,
so it's better to remove them after assembling final image.
(From OE-Core rev: 51171b4aa10f2218c5e27d785ca7bf4f3949a4b4)
Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>