Don't prevent boot on temp cleanup

Fixes #2462
Fixes #2455

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

mount/temp_unsupported.go

@@ -24,6 +24,6 @@ func SetTempMountLocation(root string) error {
 }
 
 // CleanupTempMounts all temp mounts and remove the directories
-func CleanupTempMounts(flags int) error {
-	return nil
+func CleanupTempMounts(flags int) ([]error, error) {
+	return nil, nil
 }