drivers: net: xgene: Rewrite buggy loop in xgene_enet_ecc_init()

drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function

Depending on the arbitrary value on the stack, the loop may terminate
too early, and cause a bogus -ENODEV failure.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c

@@ -124,20 +124,18 @@ static int xgene_enet_ecc_init(struct xgene_enet_pdata *p)
 {
 	struct net_device *ndev = p->ndev;
 	u32 data;
-	int i;
+	int i = 0;
 
 	xgene_enet_wr_diag_csr(p, ENET_CFG_MEM_RAM_SHUTDOWN_ADDR, 0);
-	for (i = 0; i < 10 && data != ~0U ; i++) {
+	do {
 		usleep_range(100, 110);
 		data = xgene_enet_rd_diag_csr(p, ENET_BLOCK_MEM_RDY_ADDR);
-	}
+		if (data == ~0U)
+			return 0;
+	} while (++i < 10);
 
-	if (data != ~0U) {
 	netdev_err(ndev, "Failed to release memory from shutdown\n");
 	return -ENODEV;
-	}
-
-	return 0;
 }
 
 static void xgene_enet_config_ring_if_assoc(struct xgene_enet_pdata *p)