iwlagn: remove most BUG_ON instances

There are a number of things in the driver that
may result in a BUG(), which is suboptimal since
it's hard to get debugging information out of
the driver in that case and the user experience
is also not good :-)

Almost all BUG_ON instances can be converted to
WARN_ON with a few lines of appropriate error
handling, so do that instead.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index b4f7510..0daeded 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -394,7 +394,9 @@
 		return -EINVAL;
 	}
 
-	BUG_ON(addr & ~DMA_BIT_MASK(36));
+	if (WARN_ON(addr & ~DMA_BIT_MASK(36)))
+		return -EINVAL;
+
 	if (unlikely(addr & ~IWL_TX_DMA_MASK))
 		IWL_ERR(priv, "Unaligned address = %llx\n",
 			  (unsigned long long)addr);
@@ -718,7 +720,10 @@
 		/* If an RXB doesn't have a Rx queue slot associated with it,
 		 * then a bug has been introduced in the queue refilling
 		 * routines -- catch it here */
-		BUG_ON(rxb == NULL);
+		if (WARN_ON(rxb == NULL)) {
+			i = (i + 1) & RX_QUEUE_MASK;
+			continue;
+		}
 
 		rxq->queue[i] = NULL;