net/cxgbe: remove useless address check

net/cxgbe: remove useless address check

reported by "gcc (GCC) 12.0.0 20211003 (experimental)":

../drivers/net/cxgbe/cxgbe_ethdev.c:
	In function ‘cxgbe_dev_rx_queue_setup’:
../drivers/net/cxgbe/cxgbe_ethdev.c:682:24:
	error: the comparison will always evaluate as ‘true’ for the
	address of ‘fl’ will never be NULL [-Werror=address]
  682 |         if ((&rxq->fl) != NULL)
      |                        ^~

Fixing it by removing useless check.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Reviewed-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>