Update source for Rust 1.78.0

Test: m rust
Bug: 333887339
Change-Id: Ie9c8e4942f14dc39d711e270cf0d3877aa7057c3
diff --git a/libs/libfdt/src/libfdt.rs b/libs/libfdt/src/libfdt.rs
index 1af9edf..9ddfbaa 100644
--- a/libs/libfdt/src/libfdt.rs
+++ b/libs/libfdt/src/libfdt.rs
@@ -311,6 +311,7 @@
     }
 
     /// Safe wrapper around `fdt_open_into()` (C function).
+    #[allow(dead_code)]
     fn open_into(&self, dest: &mut [u8]) -> Result<()> {
         let fdt = self.as_fdt_slice().as_ptr().cast();