net: netxen: fix a missing check and an uninitialized use

When netxen_rom_fast_read() fails, "bios" is left uninitialized and may
contain random value, thus should not be used.

The fix ensures that if netxen_rom_fast_read() fails, we return "-EIO".
Signed-off-by: NKangjie Lu <kjlu@umn.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c

@@ -1125,7 +1125,8 @@ netxen_validate_firmware(struct netxen_adapter *adapter)
 		return -EINVAL;
 	}
 	val = nx_get_bios_version(adapter);
-	netxen_rom_fast_read(adapter, NX_BIOS_VERSION_OFFSET, (int *)&bios);
+	if (netxen_rom_fast_read(adapter, NX_BIOS_VERSION_OFFSET, (int *)&bios))
+		return -EIO;
 	if ((__force u32)val != bios) {
 		dev_err(&pdev->dev, "%s: firmware bios is incompatible\n",
 				fw_name[fw_type]);