[host] nvfbc: optimize change detection loop

Before, we only break out of the current row when a change is detected,
and all subsequent rows are still scanned. Now we break out of the entire
loop. This should make change detection ever so slightly faster.

host/platform/Windows/capture/NVFBC/src/nvfbc.c

@@ -305,9 +305,10 @@ static CaptureResult nvfbc_capture(void)
       if (this->diffMap[(y*w)+x])
       {
         changed = true;
-        break;
+        goto done;
       }
 
+done:
   if (!changed)
     return CAPTURE_RESULT_TIMEOUT;