m: enable dm-verity rootfs

This makes all the existing EFI unified kernel images boot from a
dm-verity rootfs.

Change-Id: Iac05942e40b81825252e84feb5c79c8ff215680a
Reviewed-on: https://review.monogon.dev/c/monogon/+/527
Reviewed-by: Sergiusz Bazanski <serge@monogon.tech>
diff --git a/metropolis/installer/main.go b/metropolis/installer/main.go
index 4e6d6e0..520bc89 100644
--- a/metropolis/installer/main.go
+++ b/metropolis/installer/main.go
@@ -242,7 +242,7 @@
 		panicf("Cannot open EFI payload in bundle: %v", err)
 	}
 	defer efiPayload.Close()
-	systemImage, err := bundle.Open("rootfs.img")
+	systemImage, err := bundle.Open("verity_rootfs.img")
 	if err != nil {
 		panicf("Cannot open system image in bundle: %v", err)
 	}