mwifiex: don't do unbalanced free()'ing in cleanup_if()

The cleanup_if() callback is the inverse of init_if(). We allocate our
'card' interface structure in the probe() function, but we free it in
cleanup_if(). That gives a few problems:
(a) we leak this memory if probe() fails before we reach init_if()
(b) we can't safely utilize 'card' after cleanup_if() -- namely, in
    remove() or suspend(), both of which might race with the cleanup
    paths in our asynchronous FW initialization path

Solution: just use devm_kzalloc(), which will free this structure
properly when the device is removed -- and drop the set_drvdata(...,
NULL), since the driver core does this for us. This also removes the
temptation to use drvdata == NULL as a hack for checking if the device
has been "cleaned up."

I *do* leave the set_drvdata(..., NULL) for the hacky SDIO
mwifiex_recreate_adapter(), since the device core won't be able to clear
that one for us.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
index 063c707..3047c1a 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -189,7 +189,7 @@ static int mwifiex_pcie_probe(struct pci_dev *pdev,
 	pr_debug("info: vendor=0x%4.04X device=0x%4.04X rev=%d\n",
 		 pdev->vendor, pdev->device, pdev->revision);
 
-	card = kzalloc(sizeof(struct pcie_service_card), GFP_KERNEL);
+	card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL);
 	if (!card)
 		return -ENOMEM;
 
@@ -2815,7 +2815,6 @@ static int mwifiex_pcie_init(struct mwifiex_adapter *adapter)
 err_set_dma_mask:
 	pci_disable_device(pdev);
 err_enable_dev:
-	pci_set_drvdata(pdev, NULL);
 	return ret;
 }
 
@@ -2849,9 +2848,7 @@ static void mwifiex_pcie_cleanup(struct mwifiex_adapter *adapter)
 		pci_disable_device(pdev);
 		pci_release_region(pdev, 2);
 		pci_release_region(pdev, 0);
-		pci_set_drvdata(pdev, NULL);
 	}
-	kfree(card);
 }
 
 static int mwifiex_pcie_request_irq(struct mwifiex_adapter *adapter)