scripts/copy_output.lua: delete images from OpenWrt dir after copying them

We don't move the images directly, as multiple images of the same device
may have the same source image (on x86), but only delete them after a
whole device has been handled (multiple devices using the same images
must be handled using aliases or manifest aliases instead).

scripts/copy_output.lua

@@ -31,6 +31,12 @@ mkdir(env.GLUON_IMAGEDIR..'/other')
 lib.include(target)
 
 
+local function image_source(image)
+	return string.format(
+		'openwrt/bin/targets/%s/openwrt-%s-%s%s%s',
+		bindir, openwrt_target, image.name, image.in_suffix, image.extension)
+end
+
 local function clean(image, name)
 	local dir, file = image:dest_name(name, '\0', '\0')
 	lib.exec {'rm', '-f', dir..'/'..file}
@@ -41,8 +47,7 @@ for _, images in pairs(lib.images) do
 		clean(image, image.image)
 
 		local destdir, destname = image:dest_name(image.image)
-		local source = string.format('openwrt/bin/targets/%s/openwrt-%s-%s%s%s',
-			bindir, openwrt_target, image.name, image.in_suffix, image.extension)
+		local source = image_source(image)
 
 		lib.exec {'cp', source, destdir..'/'..destname}
 
@@ -53,6 +58,11 @@ for _, images in pairs(lib.images) do
 			lib.exec {'ln', '-s', destname, destdir..'/'..aliasname}
 		end
 	end
+
+	for _, image in ipairs(images) do
+		local source = image_source(image)
+		lib.exec {'rm', '-f', source}
+	end
 end