[Driver] Fix typo "BackenJobAction" (NFC)

Author: modocache

lib/Driver/Driver.cpp

@@ -1363,7 +1363,7 @@ void Driver::buildActions(const ToolChain &TC,
   } else {
     // The merge module action needs to be first to force the right outputs
     // for the other actions. However, we can't rely on it being the only
-    // action because there may be other actions (e.g. BackenJobActions) that
+    // action because there may be other actions (e.g. BackendJobActions) that
     // are not merge-module inputs but nonetheless should be run.
     if (MergeModuleAction)
       Actions.push_back(MergeModuleAction.release());