When copying file within the same machine with "rsync", avoid
using "-z" to make it faster.
Test Plan:
Pass: build-pkgs -p initramfs-ostree
Story: 2010643
Task: 47904
Change-Id: Icc65ccbff912c7321bf36bdf177ceb0614c94b11
Signed-off-by: Zhang Xiao <xiao.zhang@windriver.com>