fix: assets upload to use the correct variable name

Signed-off-by: yash-zededa <yash@zededa.com>

.github/workflows/assets.yml

@@ -115,7 +115,7 @@ jobs:
           # Create SHA256 checksum for rootfs.img
           sha256sum "assets/rootfs.img" | awk '{ print $1 }' > "assets/rootfs.img.sha256"
           for file in assets/*; do
-            base_name=$(basename "$asset")
+            base_name=$(basename "$file")
             # Add ARCH prefix
             new_name="${ARCH}.${base_name}"
             # Rename the file