the uncontroversal gcc 4.0 compilation fixes

src/drivers/net/natsemi.c

@@ -604,7 +604,7 @@ natsemi_transmit(struct nic  *nic,
 		 const char  *p)     /* Packet */
 {
     u32 to, nstype;
-    u32 tx_status;
+    volatile u32 tx_status;
     
     /* Stop the transmitter */
     outl(TxOff, ioaddr + ChipCmd);
@@ -643,7 +643,7 @@ natsemi_transmit(struct nic  *nic,
 
     to = currticks() + TX_TIMEOUT;
 
-    while ((((volatile u32) tx_status=txd.cmdsts) & OWN) && (currticks() < to))
+    while (((tx_status=txd.cmdsts) & OWN) && (currticks() < to))
         /* wait */ ;
 
     if (currticks() >= to) {

src/drivers/net/sis900.c

@@ -1097,7 +1097,7 @@ sis900_transmit(struct nic  *nic,
                 const char  *p)     /* Packet */
 {
     u32 to, nstype;
-    u32 tx_status;
+    volatile u32 tx_status;
     
     /* Stop the transmitter */
     outl(TxDIS | inl(ioaddr + cr), ioaddr + cr);
@@ -1136,7 +1136,7 @@ sis900_transmit(struct nic  *nic,
 
     to = currticks() + TX_TIMEOUT;
 
-    while ((((volatile u32) tx_status=txd.cmdsts) & OWN) && (currticks() < to))
+    while (((tx_status=txd.cmdsts) & OWN) && (currticks() < to))
         /* wait */ ;
 
     if (currticks() >= to) {