tools: Ignore bot-generated branch creation patches

Don't force infra to change their bot because of our weird script. If
it's from the OpenStack Release Bot, it's probably good and we can skip
the backport check.

Change-Id: I682bd198a74fc252e47e8bdfb33bd21782b63ff9
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

tools/check-cherry-picks.sh

@@ -14,6 +14,11 @@ if [ $parent_number -eq 2 ]; then
     commit_hash=$(git show --format='%P' --quiet | awk '{print $NF}')
 fi
 
+if git show --format='%aE' HEAD~ --quiet | grep -qi 'infra-root@openstack.org'; then
+    echo 'Bot generated change; ignoring'
+    exit 0
+fi
+
 hashes=$(git show --format='%b' --quiet $commit_hash | sed -nr 's/^.cherry picked from commit (.*).$/\1/p')
 checked=0
 branches+=""