Re-add the boot message that was accidentally merged out

Change-Id: Ib48abb46398b908ba5526775f024a0b81f792779

utils/src/lib.rs

diff --git a/utils/src/lib.rs b/utils/src/lib.rs
index 37b2cd8..6c78251 100644
--- a/utils/src/lib.rs
+++ b/utils/src/lib.rs
@@ -60,5 +60,8 @@
         dprintf!("seL4 boot message posted\n");
 
         SMC_CONTROL_BLOCK.write_volatile(entry_point);
+
+        // This message is checked in shodan_boot.robot - keep in sync.
+        dprintf!("load_sel4() completed successfully\n");
     }
 }