tests: Standardize use of SetupRepo/Teardown

cache_test.go

@@ -8,8 +8,8 @@ import (
 )
 
 func TestCache(t *testing.T) {
-	repo := SetupRepo(t)
-	defer TeardownRepo(t, repo)
+	repo := SetupRepo()
+	defer TeardownRepo(repo)
 
 	_, err := restic.NewCache(repo, "")
 	OK(t, err)