wil6210: fix memory leak in the AP flow

When switching between STA and AP modes, memory allocated for Rx vring leaks
This is because start_ap() allocates Rx vring but stop_ap() do not free it.
Logically, Rx vring is not valid (HW can't use it anymore), so free it in reset()
Also, check double init for Rx vring and bail out with -EINVAL

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/wil6210/main.c

@@ -343,6 +343,8 @@ int wil_reset(struct wil6210_priv *wil)
 	/* TODO: put MAC in reset */
 	wil_target_reset(wil);
 
+	wil_rx_fini(wil);
+
 	/* init after reset */
 	wil->pending_connect_cid = -1;
 	reinit_completion(&wil->wmi_ready);

drivers/net/wireless/ath/wil6210/txrx.c

@@ -557,6 +557,11 @@ int wil_rx_init(struct wil6210_priv *wil)
 	struct vring *vring = &wil->vring_rx;
 	int rc;
 
+	if (vring->va) {
+		wil_err(wil, "Rx ring already allocated\n");
+		return -EINVAL;
+	}
+
 	vring->size = WIL6210_RX_RING_SIZE;
 	rc = wil_vring_alloc(wil, vring);
 	if (rc)