p54: fix a null pointer dereference bug

SVN-Revision: 25775

package/mac80211/patches/710-p54_rssi_crash_fix.patch

@@ -0,0 +1,18 @@
+--- a/drivers/net/wireless/p54/eeprom.c
++++ b/drivers/net/wireless/p54/eeprom.c
+@@ -524,10 +524,13 @@ err_data:
+ 
+ struct p54_rssi_db_entry *p54_rssi_find(struct p54_common *priv, const u16 freq)
+ {
+-	struct p54_rssi_db_entry *entry = (void *)(priv->rssi_db->data +
+-						   priv->rssi_db->offset);
++	struct p54_rssi_db_entry *entry;
+ 	int i, found = -1;
+ 
++	if (!priv->rssi_db)
++		return &p54_rssi_default;
++
++	entry = (void *)(priv->rssi_db->data + priv->rssi_db->offset);
+ 	for (i = 0; i < priv->rssi_db->entries; i++) {
+ 		if (!same_band(freq, entry[i].freq))
+ 			continue;