Speculative fix for missing cws-log.txt file

Bug: twpowertools:20

Change-Id: I61c0b0e8c50a38f5d47b25c656248323d989f4a6
diff --git a/roles/cws-publish/tasks/main.yaml b/roles/cws-publish/tasks/main.yaml
index c263d24..66c9ae1 100644
--- a/roles/cws-publish/tasks/main.yaml
+++ b/roles/cws-publish/tasks/main.yaml
@@ -35,6 +35,7 @@
       --source {{ zuul.project.src_dir|quote }}/out/{{ zip_file.stdout|quote }}
       --client-id {{ credentials.clientId|quote }} --refresh-token {{ credentials.refreshToken|quote }}
       2>cws-log.txt
+    chdir: "{{ zuul.project.src_dir }}"
   no_log: True
   register: uploadcmd
   failed_when: