enic: fix return value in _vnic_dev_cmd

Hardware (in readq(&devcmd->args[0])) returns positive number in case of error.
But _vnic_dev_cmd should return a negative value in case of error.
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cisco/enic/vnic_dev.c

@@ -312,12 +312,12 @@ static int _vnic_dev_cmd(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
 				err = (int)readq(&devcmd->args[0]);
 				if (err == ERR_EINVAL &&
 				    cmd == CMD_CAPABILITY)
-					return err;
+					return -err;
 				if (err != ERR_ECMDUNKNOWN ||
 				    cmd != CMD_CAPABILITY)
 					pr_err("Error %d devcmd %d\n",
 						err, _CMD_N(cmd));
-				return err;
+				return -err;
 			}
 
 			if (_CMD_DIR(cmd) & _CMD_DIR_READ) {