osbase/build: update progress messages to contain output short_name

Change-Id: Id41a05a7b8f5cec6e50d9c74ee09309d1a4b504f
Reviewed-on: https://review.monogon.dev/c/monogon/+/3691
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/osbase/build/def.bzl b/osbase/build/def.bzl
index af2562b..b2dfe91 100644
--- a/osbase/build/def.bzl
+++ b/osbase/build/def.bzl
@@ -278,7 +278,7 @@
     table = ctx.actions.declare_file(ctx.attr.name + ".dmt")
     ctx.actions.run(
         mnemonic = "GenVerityImage",
-        progress_message = "Generating a dm-verity image",
+        progress_message = "Generating a dm-verity image: {}".format(image.short_path),
         inputs = [ctx.file.source],
         outputs = [
             image,