net: usb: initialize tmp in dm9601.c to avoid warning

In two places, tmp is initialized implicitly by being passed as a
pointer during a function call.  However, this is not obvious to the
compiler, which logs a warning.
Signed-off-by: Simon Que <sque@chromium.org>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/dm9601.c

@@ -122,7 +122,7 @@ static int dm_read_shared_word(struct usbnet *dev, int phy, u8 reg, __le16 *valu
 	dm_write_reg(dev, DM_SHARED_CTRL, phy ? 0xc : 0x4);
 
 	for (i = 0; i < DM_TIMEOUT; i++) {
-		u8 tmp;
+		u8 tmp = 0;
 
 		udelay(1);
 		ret = dm_read_reg(dev, DM_SHARED_CTRL, &tmp);
@@ -165,7 +165,7 @@ static int dm_write_shared_word(struct usbnet *dev, int phy, u8 reg, __le16 valu
 	dm_write_reg(dev, DM_SHARED_CTRL, phy ? 0x1a : 0x12);
 
 	for (i = 0; i < DM_TIMEOUT; i++) {
-		u8 tmp;
+		u8 tmp = 0;
 
 		udelay(1);
 		ret = dm_read_reg(dev, DM_SHARED_CTRL, &tmp);