net/avf: fix performance drop after port reset

[ upstream commit 63b7be7 ]

Needs to reset rxq->rxrearm_start to 0 when reset_rx_queue(),
otherwise, the random value of rxrearm_start will cause performance drop
due to L3 contested accesses.

Fixes: 69dd4c3 ("net/avf: enable queue and device")

Signed-off-by: Leyi Rong <leyi.rong@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>

drivers/net/avf/avf_rxtx.c

@@ -170,6 +170,7 @@ reset_rx_queue(struct avf_rx_queue *rxq)
 	rxq->pkt_first_seg = NULL;
 	rxq->pkt_last_seg = NULL;
 	rxq->rxrearm_nb = 0;
+	rxq->rxrearm_start = 0;
 }
 
 static inline void