[wasm] Fix missing {CompilationState} field initialization.

R=clemensh@chromium.org

Change-Id: Icba445650131dcd54495f40f194ffe64cce24f94
Reviewed-on: https://chromium-review.googlesource.com/c/1317587Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57233}

src/wasm/module-compiler.cc

@@ -234,7 +234,7 @@ class CompilationStateImpl {
 
   // The foreground task to log finished wasm code. Is {nullptr} if no such task
   // is currently scheduled.
-  LogCodesTask* log_codes_task_;
+  LogCodesTask* log_codes_task_ = nullptr;
 
   // End of fields protected by {mutex_}.
   //////////////////////////////////////////////////////////////////////////////