test: fix path

Author: durran

.evergreen/config.in.yml

@@ -888,7 +888,7 @@ functions:
           cd ${DRIVERS_TOOLS}/.evergreen/auth_aws
           . ./activate-authawsvenv.sh
           export MONGODB_BINARIES="${MONGODB_BINARIES}";
-          export PROJECT_DIRECTORY=$ECS_SRC_DIR;
+          export PROJECT_DIRECTORY=$PROJECT_DIRECTORY;
           python aws_tester.py ecs
 
   "run-ocsp-test":