Change of recv_n_pool_free_frames default value in InnoDB patches has no effect

In innodb51.patch and innodb51_builtin.patch we try to raise the default value of recv_n_pool_free_frames from 256 to 1024. I think it doesn't work as intended due to the following code in recv_sys_init():

 /* Set appropriate value of recv_n_pool_free_frames. */
 if (buf_pool_get_curr_size() >= (10 * 1024 * 1024)) {
  /* Buffer pool of size greater than 10 MB. */
  recv_n_pool_free_frames = 512;
 }

So if the buffer pool is larger than 10 MB (which is always the case these days) it is "adjusted" to 512, which in case of XtraBackup is actually lower than the re-defined default.