Bug 562628. Propagate nsProcess::Init failures back to LaunchWithIProcess. r=bzbarsky

uriloader/exthandler/nsMIMEInfoImpl.cpp

@@ -383,7 +383,8 @@ nsMIMEInfoBase::InitProcess(nsIFile* aApp, nsresult* aResult)
   if (NS_FAILED(*aResult))
     return nsnull;
 
-  if (NS_FAILED(process->Init(aApp)))
+  *aResult = process->Init(aApp);
+  if (NS_FAILED(*aResult))
     return nsnull;
 
   return process.forget();