Fix flaky content lookup in test_prn.sh

Author: jobselko

tests/scripts/pulp_file/test_prn.sh

@@ -34,7 +34,7 @@ expect_fail pulp -v file remote show --remote "${repository_prn}"
 
 # Test sync
 expect_succ pulp -v file repository sync --repository "${repository_prn}" --remote "${remote_prn}"
-file_prn=$(pulp file content list --limit 1 --offset 0 | jq -r .[].prn)
+file_prn=$(pulp file content list --repository "${repository_prn}" --limit 1 --offset 0 | jq -r .[].prn)
 
 # Test update
 expect_succ pulp -v file repository update --repository "${repository_prn}" --remote "${remote_prn}"