Lock inside FetchOrdinalNames just in case

* It's possible for two threads to hit GetProcAddress on the same module at
  once, try to late-fetch the ordinals, and clash. If we lock then only one
  thread will perform the fetch, the other thread can wait and bail out once it
  finds the ordinals already filled out.

renderdoc/os/win32/win32_hook.cpp

@@ -98,9 +98,16 @@ struct DllHookset
   DWORD OrdinalBase = 0;
   vector<string> OrdinalNames;
   std::vector<FunctionLoadCallback> Callbacks;
+  Threading::CriticalSection ordinallock;
 
   void FetchOrdinalNames()
   {
+    SCOPED_LOCK(ordinallock);
+
+    // return if we already fetched the ordinals
+    if(!OrdinalNames.empty())
+      return;
+
     byte *baseAddress = (byte *)module;
 
 #if ENABLED(VERBOSE_DEBUG_HOOK)