drivers/net/wireless/prism54: fix sparse warning: fix signedness

Fix sparse warning:
  drivers/net/wireless/prism54/isl_ioctl.c:2997:32: warning: incorrect type in argument 2 (different signedness)
  drivers/net/wireless/prism54/oid_mgt.c:712:42: warning: incorrect type in argument 2 (different signedness)
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/wireless/prism54/isl_ioctl.c

@@ -2981,7 +2981,8 @@ prism54_set_spy(struct net_device *ndev,
 		union iwreq_data *uwrq, char *extra)
 {
 	islpci_private *priv = netdev_priv(ndev);
-	u32 u, oid = OID_INL_CONFIG;
+	u32 u;
+	enum oid_num_t oid = OID_INL_CONFIG;
 
 	down_write(&priv->mib_sem);
 	mgt_get(priv, OID_INL_CONFIG, &u);

drivers/net/wireless/prism54/oid_mgt.c

@@ -698,7 +698,7 @@ int
 mgt_commit(islpci_private *priv)
 {
 	int rvalue;
-	u32 u;
+	enum oid_num_t u;
 
 	if (islpci_get_state(priv) < PRV_STATE_INIT)
 		return 0;