Fixed typo in run_tests.sh file

Change-Id: Iba14b5279719913b6ed738f5114515f2552f3717
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index f44058c..9a4e8ea 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -113,7 +113,7 @@
 }
 
 salt_run() {
-    [ -e ${VEN_DIR}/bin/activate ] && source ${VENV_DIR}/bin/activate
+    [ -e ${VENV_DIR}/bin/activate ] && source ${VENV_DIR}/bin/activate
     salt-call ${SALT_OPTS} $*
 }