treewide: initialize empty structs with var

Change-Id: I72d3993eaf5fe57c77b1dda8218e36a8cc11813d
Reviewed-on: https://review.monogon.dev/c/monogon/+/3108
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/cloud/shepherd/manager/control_loop.go b/cloud/shepherd/manager/control_loop.go
index 7a05658..3e5c832 100644
--- a/cloud/shepherd/manager/control_loop.go
+++ b/cloud/shepherd/manager/control_loop.go
@@ -122,7 +122,7 @@
 func (r *controlLoopRunner) run(ctx context.Context, conn *bmdb.Connection) error {
 	pinfo := r.loop.getProcessInfo()
 
-	eg := errgroup.Group{}
+	var eg errgroup.Group
 	for j := 0; j < r.config.Parallelism; j += 1 {
 		eg.Go(func() error {
 			return r.runOne(ctx, conn, &pinfo)