minor changes to darwin build script

scripts/eosio_build_darwin.sh

@@ -172,7 +172,7 @@
 		brew install --force pkgconfig
 		brew unlink pkgconfig && brew link --force pkgconfig
 		STATUS=$(curl -LO -w '%{http_code}' --connect-timeout 30 https://github.com/mongodb/mongo-c-driver/releases/download/1.9.3/mongo-c-driver-1.9.3.tar.gz)
-		if [ $STATUS -ne 200 ]; then
+		if [ "${STATUS}" -ne 200 ]; then
 			rm -f ${TEMP_DIR}/mongo-c-driver-1.9.3.tar.gz
 			printf "\tUnable to download MongoDB C driver at this time.\n"
 			printf "\tExiting now.\n\n"