m68k: kill skb_copy_from_linear_data compiler warnings

The recent conversion from `memcpy' to `skb_copy_from_linear_data' removed a
few casts, which were needed to silence compiler warnings. Re-add them.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/net/7990.c b/drivers/net/7990.c
index d396f99..0877fc3 100644
--- a/drivers/net/7990.c
+++ b/drivers/net/7990.c
@@ -565,9 +565,9 @@
         ib->btx_ring [entry].length = (-len) | 0xf000;
         ib->btx_ring [entry].misc = 0;
 
-    	if (skb->len < ETH_ZLEN)
-    		memset((char *)&ib->tx_buf[entry][0], 0, ETH_ZLEN);
-        skb_copy_from_linear_data(skb, &ib->tx_buf[entry][0], skblen);
+	if (skb->len < ETH_ZLEN)
+		memset((void *)&ib->tx_buf[entry][0], 0, ETH_ZLEN);
+        skb_copy_from_linear_data(skb, (void *)&ib->tx_buf[entry][0], skblen);
 
         /* Now, give the packet to the lance */
         ib->btx_ring [entry].tmd1_bits = (LE_T1_POK|LE_T1_OWN);