net: variables reach -1, but 0 tested

while (timeout--) { ... }

timeout becomes -1 if the loop isn't ended otherwise, not 0.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c
index d5d53b6..0bf2114 100644
--- a/drivers/net/tulip/de2104x.c
+++ b/drivers/net/tulip/de2104x.c
@@ -392,7 +392,7 @@
 	unsigned drop = 0;
 	int rc;
 
-	while (rx_work--) {
+	while (--rx_work) {
 		u32 status, len;
 		dma_addr_t mapping;
 		struct sk_buff *skb, *copy_skb;