efi: install grub.cfg under new vendor during updates

When doing switches from RHEL 10 to Fedora 43, after reboot, check
grub.cfg and bootuuid.cfg are in old vendor redhat, that will make
the machine fails to boot a second time since grub.cfg cannot be
found.

We need to install the 2 files under new vendor during updates.

See #1024

Author: HuijingHei

src/efi.rs

@@ -483,12 +483,31 @@ impl Component for Efi {
 
         for esp in esp_devices {
             let destpath = &self.ensure_mounted_esp(rootcxt.path.as_ref(), Path::new(&esp))?;
-            let destdir = openat::Dir::open(&destpath.join("EFI")).context("opening EFI dir")?;
+            let dest_efi = destpath.join("EFI");
+            let destdir = openat::Dir::open(&dest_efi).context("opening EFI dir")?;
             validate_esp_fstype(&destdir)?;
+
+            // Get old vendor name from mounted efi before applying
+            let Some(old_vendor) = self.get_efi_vendor(&dest_efi)? else {
+                anyhow::bail!("Failed to find efi vendor at {}", dest_efi.display());
+            };
             log::trace!("applying diff: {}", &diff);
             filetree::apply_diff(&updated, &destdir, &diff, None)
                 .context("applying filesystem changes")?;
 
+            // Install grub.cfg under new vendor
+            {
+                // Get new vendor name
+                let sysroot = rootcxt.path.as_std_path();
+                let Some(new_vendor) = self.get_efi_vendor(&sysroot.join(&updated_path))? else {
+                    anyhow::bail!("Failed to find efi vendor in new update");
+                };
+                if new_vendor != old_vendor && destdir.exists(&old_vendor)? {
+                    grubconfigs::install(sysroot_dir, None, Some(&new_vendor), true)?;
+                    destdir.remove_all(&old_vendor)?;
+                }
+            }
+
             // Do the sync before unmount
             fsfreeze_thaw_cycle(destdir.open_file(".")?)?;
             drop(destdir);
@@ -609,7 +628,7 @@ impl Component for Efi {
 
         // Does not support multiple shim for efi
         if shim_files.len() > 1 {
-            anyhow::bail!("Found multiple {SHIM} in the image");
+            anyhow::bail!("Found multiple {SHIM} in the image: {:?}", shim_files);
         }
         if let Some(p) = shim_files.first() {
             let p = p