net: more timeouts that reach -1

with while (timeout-- > 0); timeout reaches -1 after the loop, so the tests
below are off by one. also don't do an '< 0' test on an unsigned.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/jme.c b/drivers/net/jme.c
index 08b3405..a6e1a35 100644
--- a/drivers/net/jme.c
+++ b/drivers/net/jme.c
@@ -957,13 +957,14 @@
 		goto out_inc;
 
 	i = atomic_read(&rxring->next_to_clean);
-	while (limit-- > 0) {
+	while (limit > 0) {
 		rxdesc = rxring->desc;
 		rxdesc += i;
 
 		if ((rxdesc->descwb.flags & cpu_to_le16(RXWBFLAG_OWN)) ||
 		!(rxdesc->descwb.desccnt & RXWBDCNT_WBCPL))
 			goto out;
+		--limit;
 
 		desccnt = rxdesc->descwb.desccnt & RXWBDCNT_DCNT;