Bug 1604600-Remove redundant return in void function. r=sylvestre

Differential Revision: https://phabricator.services.mozilla.com/D57933

--HG--
extra : moz-landing-system : lando

js/src/util/StructuredSpewer.cpp

@@ -80,7 +80,6 @@ void StructuredSpewer::tryToInitializeOutput(const char* path) {
   // These logs are structured as a JSON array.
   output_.put("[");
   json_.emplace(output_);
-  return;
 }
 
 // Treat pattern like a glob, and return true if pattern exists