[PATCH] prism54 Fix reference to uninitialized pointer

* oid_mgt.c is calling islpci_mgt_transaction passing the address
  of a pointer to the management frame. This is not being
  initialized by the caller. The callee only updates this
  pointer when successful. When not, boom.

* Being ultracautious again, not only initialize in the caller,
  also null out the pointer unconditionally in the callee.

drivers/net/wireless/prism54/islpci_mgt.c

@@ -458,6 +458,8 @@ islpci_mgt_transaction(struct net_device *ndev,
 	int err;
 	DEFINE_WAIT(wait);
 
+	*recvframe = NULL;
+
 	if (down_interruptible(&priv->mgmt_sem))
 		return -ERESTARTSYS;
 

drivers/net/wireless/prism54/oid_mgt.c

@@ -408,7 +408,7 @@ int
 mgt_set_request(islpci_private *priv, enum oid_num_t n, int extra, void *data)
 {
 	int ret = 0;
-	struct islpci_mgmtframe *response;
+	struct islpci_mgmtframe *response = NULL;
 	int response_op = PIMFOR_OP_ERROR;
 	int dlen;
 	void *cache, *_data = data;
@@ -620,7 +620,7 @@ static enum oid_num_t commit_part2[] = {
 static int
 mgt_update_addr(islpci_private *priv)
 {
-	struct islpci_mgmtframe *res;
+	struct islpci_mgmtframe *res = NULL;
 	int ret;
 
 	ret = islpci_mgt_transaction(priv->ndev, PIMFOR_OP_GET,