message: Simplify pin_wasm()
diff: @@ -124,16 +124,11 @@ where
  ///
  /// If the given ID is not found, or the content does not match the hash (=ID), an error is returned.
  pub fn pin_wasm(&mut self, checksum: &Checksum) -> VmResult<()> {
  - let code = load_wasm_from_disk(&self.wasm_path, checksum)?;
  - // verify hash matches (integrity check)
  - if Checksum::generate(&code) != *checksum {
  - Err(VmError::integrity_err())
  - } else {
  - // store into the pinned cache
  + let code = self.load_wasm(checksum)?;
  + // compile and store into the pinned cache
  let module = compile_only(code.as_slice())?;
  self.pinned_memory_cache.store(checksum, module)
  }
  - }
  /// Unpins a Wasm, i.e. removes it from the pinned memory cache.
  ///
  