b43: Fix warnings from gcc 4.6.0

gcc 4.6.0 warnings for b43:

  CC [M]  drivers/net/wireless/b43/lo.o
drivers/net/wireless/b43/lo.c: In function ‘lo_measure_gain_values’:
drivers/net/wireless/b43/lo.c:304:7: warning: variable ‘trsw_rx’ set but not used [-Wunused-but-set-variable]
  CC [M]  drivers/net/wireless/b43/dma.o
drivers/net/wireless/b43/dma.c: In function ‘free_all_descbuffers’:
drivers/net/wireless/b43/dma.c:760:30: warning: variable ‘desc’ set but not used [-Wunused-but-set-variable]
drivers/net/wireless/b43/dma.c: In function ‘b43_dma_handle_txstatus’:
drivers/net/wireless/b43/dma.c:1391:30: warning: variable ‘desc’ set but not used [-Wunused-but-set-variable]

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index 11e66cd..d02cf83 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -757,14 +757,14 @@
 
 static void free_all_descbuffers(struct b43_dmaring *ring)
 {
-	struct b43_dmadesc_generic *desc;
 	struct b43_dmadesc_meta *meta;
 	int i;
 
 	if (!ring->used_slots)
 		return;
 	for (i = 0; i < ring->nr_slots; i++) {
-		desc = ring->ops->idx2desc(ring, i, &meta);
+		/* get meta - ignore returned value */
+		ring->ops->idx2desc(ring, i, &meta);
 
 		if (!meta->skb || b43_dma_ptr_is_poisoned(meta->skb)) {
 			B43_WARN_ON(!ring->tx);
@@ -1388,7 +1388,6 @@
 {
 	const struct b43_dma_ops *ops;
 	struct b43_dmaring *ring;
-	struct b43_dmadesc_generic *desc;
 	struct b43_dmadesc_meta *meta;
 	int slot, firstused;
 	bool frame_succeed;
@@ -1416,7 +1415,8 @@
 	ops = ring->ops;
 	while (1) {
 		B43_WARN_ON(slot < 0 || slot >= ring->nr_slots);
-		desc = ops->idx2desc(ring, slot, &meta);
+		/* get meta - ignore returned value */
+		ops->idx2desc(ring, slot, &meta);
 
 		if (b43_dma_ptr_is_poisoned(meta->skb)) {
 			b43dbg(dev->wl, "Poisoned TX slot %d (first=%d) "