rustjail: Fix needless_borrow warnings

As we bumped the rust toolchain to 1.66.0, some new warnings have been
raised due to needless_borrow.

Let's fix them all here.

For more info about the warnings, please, take a look at:
https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>

src/agent/rustjail/src/mount.rs

@@ -782,7 +782,7 @@ fn mount_from(
             Path::new(&dest).parent().unwrap()
         };
 
-        fs::create_dir_all(&dir).map_err(|e| {
+        fs::create_dir_all(dir).map_err(|e| {
             log_child!(
                 cfd_log,
                 "create dir {}: {}",