[source] image.mk: Generate cpiogz with root-owned files

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/dbaaeae428d1d1d7cc326d5ac9bb9b5b967f960f

commit dbaaeae428d1d1d7cc326d5ac9bb9b5b967f960f
Author: Michal Sojka <sojkam1 at fel.cvut.cz>
AuthorDate: Tue May 2 16:57:18 2017 +0200

    image.mk: Generate cpiogz with root-owned files
    
    Some files (e.g. /etc/dropbear) need to be owned by root. Add cpio
    option to ensure that.
    
    Other image types (at least targz and squashfs) already have this.
    
    Signed-off-by: Michal Sojka <sojkam1 at fel.cvut.cz>
---
 include/image.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/image.mk b/include/image.mk
index 8f55627..84b46f2 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -277,7 +277,7 @@ endif
 
 ifdef CONFIG_TARGET_ROOTFS_CPIOGZ
   define Image/Build/cpiogz
-	( cd $(TARGET_DIR); find . | cpio -o -H newc | gzip -9n >$(BIN_DIR)/$(IMG_PREFIX)-rootfs.cpio.gz )
+	( cd $(TARGET_DIR); find . | cpio -o -H newc -R root:root | gzip -9n >$(BIN_DIR)/$(IMG_PREFIX)-rootfs.cpio.gz )
   endef
 endif