meta/recipes-support/lz4/lz4_svn.bb defines CC=${TARGET_PREFIX}gcc, which lost the --sysroot and was incorrect, it would cause unexpected errors, we should define it as CC=${CC}.
Merged: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=2b7edd5d15592ddda0ca91c95d7ad18f5a030a85