gianfar: Remove 'maybe-uninitialized' compile warning

Warning message:
warning: 'budget_per_q' may be used uninitialized in this function

budget_per_q won't be used uninitialized since the only time
it doesn't get initialized is when entering gfar_poll with
num_act_queues == 0, meaning rstat_rxf == 0, in which case
budget_per_q is not utilized (as it has no meaning).
Inititalize budget_per_q to 0 though to suppress this compile
warning.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar.c

@@ -2838,7 +2838,7 @@ static int gfar_poll(struct napi_struct *napi, int budget)
 	struct gfar_priv_tx_q *tx_queue = NULL;
 	struct gfar_priv_rx_q *rx_queue = NULL;
 	int work_done = 0, work_done_per_q = 0;
-	int i, budget_per_q;
+	int i, budget_per_q = 0;
 	int has_tx_work;
 	unsigned long rstat_rxf;
 	int num_act_queues;