[gcc] Fix warning in Turboprop

Change-Id: I87d9d9a86edfed6112cdc5c7576e85bd5ae5f047
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3755141Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81632}

src/compiler/turboshaft/decompression-optimization.cc

@@ -52,7 +52,7 @@ struct DecompressionAnalyzer : AnalyzerBase {
     return NeedsDecompression(graph.Index(op));
   }
   bool MarkAsNeedsDecompression(OpIndex op) {
-    return needs_decompression[op] = true;
+    return (needs_decompression[op] = true);
   }
 
   template <bool is_loop>