Change personality inject path to /

The CirrOS image root disk is empty, it's only populated during
boot from the initrd image. So we can only safely inject files
before boot into '/' directly.

Closes-bug: #1646002

Depends-on: I405793b9e145308e51a08710d8e5df720aec6fde
Change-Id: I2092059acdeab0755215e7ae690e243b5b4df367
diff --git a/tempest/api/compute/servers/test_server_personality.py b/tempest/api/compute/servers/test_server_personality.py
index e5ad7b4..6688849 100644
--- a/tempest/api/compute/servers/test_server_personality.py
+++ b/tempest/api/compute/servers/test_server_personality.py
@@ -118,7 +118,9 @@
             raise self.skipException("No limit for personality files")
         person = []
         for i in range(0, int(max_file_limit)):
-            path = '/etc/test' + str(i) + '.txt'
+            # NOTE(andreaf) The cirros disk image is blank before boot
+            # so we can only inject safely to /
+            path = '/test' + str(i) + '.txt'
             person.append({
                 'path': path,
                 'contents': base64.encode_as_text(file_contents),