[tests/selinux] pr775-checkpolicy-revdeps: tests-pr.yml: Fetch upstream master and compare against it

[Ondrej Mosnacek <omosnace@redhat.com>]

            A new commit has been pushed.

            Repo   : tests/selinux
            Branch : pr775-checkpolicy-revdeps
            Commit : 5d370b95d0a2b941bed3f0595a84f547f28c6c41
            Author : Ondrej Mosnacek <omosnace@redhat.com>
            Date   : 2020-10-23T16:08:03+02:00
            Stats  : +2/-1 in 1 file(s)
            URL    : https://src.fedoraproject.org/tests/selinux/c/5d370b95d0a2b941bed3f0595a84f547f28c6c41?branch=pr775-checkpolicy-revdeps

            Log:
            tests-pr.yml: Fetch upstream master and compare against it

Rather than relying on origin/master, fetch a fresh master branch from
the upstream repo by URL. After the Fedora CI migration to testing farm,
origin == the fork and not the target repository. This should work
around it.

See also:
https://pagure.io/fedora-ci/general/issue/158

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>

---
diff --git a/tests-pr.yml b/tests-pr.yml
index dcdba5d..1f8bea8 100644
--- a/tests-pr.yml
+++ b/tests-pr.yml
@@ -5,7 +5,8 @@
   pre_tasks:
     - name: Generate list of tests in this PR
       shell: |
-          git log --format= --stat --name-only origin/master..HEAD | sed '/\//!d;s#\(.*\)/.*#\1#' | sort -u | xargs
+          git fetch https://src.fedoraproject.org/tests/selinux.git master:upstream-master
+          git log --format= --stat --name-only upstream-master..HEAD | sed '/\//!d;s#\(.*\)/.*#\1#' | sort -u | xargs
       delegate_to: localhost
       register: tests_list