coverity.sh: use a comma to separate module names

Otherwise Python bails out with
```
Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'json' is not defined
```

See https://travis-ci.org/systemd/systemd/jobs/397490437

diff --git a/tools/coverity.sh b/tools/coverity.sh
index 40acbb0411bd9df67a677dde3d52998aade054e7..1fc5b1cf990af86ea16d669dce1156782298d1c6 100755 (executable)
--- a/tools/coverity.sh
+++ b/tools/coverity.sh
@@ -46,7 +46,7 @@ else
   if [ "$AUTH" = "True" ]; then
     echo -e "\033[33;1mCoverity Scan analysis authorized per quota.\033[0m"
   else
-    WHEN=`echo $AUTH_RES | python -c "import sys; json; print(json.load(sys.stdin)['next_upload_permitted_at'])"`
+    WHEN=`echo $AUTH_RES | python -c "import sys, json; print(json.load(sys.stdin)['next_upload_permitted_at'])"`
     echo -e "\033[33;1mCoverity Scan analysis NOT authorized until $WHEN.\033[0m"
     exit 0
   fi