Fixed typo in run_tests.sh file

Change-Id: I482d2deff660f51ae6279368f2caf4e0887095ae
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index c2f7f77..3e3cf91 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -124,7 +124,7 @@
 }
 
 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} $*
 }