Refresh module handle if NULL when hitting GetProcAddress

* This might be a more serious problem in future...
* We only hook all loaded modules once, at init time, in Win32_IAT_EndHooks
* If a LoadLibrary call afterwards implicitly loads some modules we don't
  see them. Potentially we should rehook all loaded modules again each time
  LoadLibrary is called but then there would be a lot of redundant work
  unless we tracked module unload/loads to see if a module has been hooked
  before or not. For now assume we don't need to hook these modules and
  get away with just updating module handles

renderdoc/os/win32/win32_hook.cpp

@@ -220,6 +220,9 @@ FARPROC WINAPI Hooked_GetProcAddress(HMODULE mod, LPCSTR func)
 	
 	for(auto it=s_HookData->DllHooks.begin(); it != s_HookData->DllHooks.end(); ++it)
 	{
+		if(it->second.module == NULL)
+			it->second.module = GetModuleHandleA(it->first.c_str());
+
 		if(mod == it->second.module)
 		{
 			FunctionHook search(func, NULL, NULL);