Merge pull request #8 from stutiredboy/fix_build_oom

fix(build.sh): CPU_CORES is null and makes compile oom

build.sh

@@ -3,6 +3,7 @@ TOPDIR="$(dirname $(readlink -f "$0"))"
 DEP_DIR=${TOPDIR}/deps/3rd/usr/local/oceanbase/deps/devel
 TOOLS_DIR=${TOPDIR}/deps/3rd/usr/local/oceanbase/devtools
 RUNTIME_DIR=${TOPDIR}/deps/3rd/home/admin/oceanbase
+CPU_CORES=`grep -c ^processor /proc/cpuinfo`
 MAKE_ARGS=(-j $CPU_CORES)
 
 function sw()