Merge #2398

2398: Fix 'variable does not need to be mutable' warnings r=Hywan a=imor

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# Description
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When I built wasmer on Windows using the `cargo build` command, I got a couple of _the variable doesn't need to be mutable_ warnings. This PR fixes those warnings.

# Review

As this is an internal change, it shouldn't require an entry in the CHANGELOG.md file.
- [ ] Add a short description of the change to the CHANGELOG.md file


Co-authored-by: Raminder Singh <[email protected]>

lib/engine-universal/src/unwind/windows_x64.rs

@@ -69,7 +69,7 @@ impl UnwindRegistry {
         self.published = true;
 
         if !self.functions.is_empty() {
-            for (base_address, mut functions) in self.functions.iter_mut() {
+            for (base_address, functions) in self.functions.iter_mut() {
                 // Windows heap allocations are 32-bit aligned, but assert just in case
                 assert_eq!(
                     (functions.as_mut_ptr() as u64) % 4,
@@ -97,7 +97,7 @@ impl Drop for UnwindRegistry {
     fn drop(&mut self) {
         if self.published {
             unsafe {
-                for mut functions in self.functions.values_mut() {
+                for functions in self.functions.values_mut() {
                     winnt::RtlDeleteFunctionTable(functions.as_mut_ptr());
                 }
             }