Vulkan: Enumerate Query Pool properly (#6167)

Turns out that ElementAt for Queue<T> runs the default implementation as it doesn't implement IList, which enumerates elements of the queue up to the given index. This code was creating `count` enumerators and iterating way more queue items than it needed to at higher counts. The solution is just to use one enumerator and break out of the loop when we get the count that we need.

3.5% of backend time was being spent _just_ enumerating at the usual spot in SMO.

src/Ryujinx.Graphics.Vulkan/Queries/CounterQueue.cs

@@ -67,9 +67,18 @@ namespace Ryujinx.Graphics.Vulkan.Queries
             lock (_queryPool)
             {
                 count = Math.Min(count, _queryPool.Count);
-                for (int i = 0; i < count; i++)
+
+                if (count > 0)
                 {
-                    _queryPool.ElementAt(i).PoolReset(cmd, ResetSequence);
+                    foreach (BufferedQuery query in _queryPool)
+                    {
+                        query.PoolReset(cmd, ResetSequence);
+
+                        if (--count == 0)
+                        {
+                            break;
+                        }
+                    }
                 }
             }
         }