toolchain: handle white spaces in sysroot dir in copy_toolchain_sysroot
When changing permissions on all directories in the staging directory,
after copying sysroot, paths that contain spaces break the call to
chmod.
With -print0 for find and -0 for xargs white spaces are correctly
interpreted.
Signed-off-by: Daniel Lang <d.lang@abatec.at>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>