Fixed warnings generated by rustc 1.57.0

This CL fixes several warnings generated by rustc 1.57.  Many of these
warnings were related to unused fields.  These fields had previously
been considered used because they were read by the Debug trait, but this
behavior changes in the new version of rustc.  These fields are now
temporarily annotated to suppress warnings until it is determined if
they are needed.

Bug: 203802952
Test: Build and boot cuttlefish
Change-Id: I4eb1f6820a086ee9645206d7861caf0b8a04284c
diff --git a/authfs/fd_server/src/aidl.rs b/authfs/fd_server/src/aidl.rs
index 92be504..ddac2bc 100644
--- a/authfs/fd_server/src/aidl.rs
+++ b/authfs/fd_server/src/aidl.rs
@@ -110,8 +110,8 @@
         F: FnOnce(&mut FdConfig) -> BinderResult<(i32, FdConfig)>,
     {
         let mut fd_pool = self.fd_pool.lock().unwrap();
-        let mut fd_config = fd_pool.get_mut(&fd).ok_or_else(|| new_errno_error(Errno::EBADF))?;
-        let (new_fd, new_fd_config) = create_fn(&mut fd_config)?;
+        let fd_config = fd_pool.get_mut(&fd).ok_or_else(|| new_errno_error(Errno::EBADF))?;
+        let (new_fd, new_fd_config) = create_fn(fd_config)?;
         if let btree_map::Entry::Vacant(entry) = fd_pool.entry(new_fd) {
             entry.insert(new_fd_config);
             Ok(new_fd)