cxl: Fix error handling in _cxl_pci_associate_default_context()

'cxl_dev_context_init()' returns an error pointer in case of error, not
NULL. So test it with IS_ERR.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/pci.c

@@ -1921,7 +1921,7 @@ static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev)
 				goto err;
 
 			ctx = cxl_dev_context_init(afu_dev);
-			if (!ctx)
+			if (IS_ERR(ctx))
 				goto err;
 
 			afu_dev->dev.archdata.cxl_ctx = ctx;

drivers/misc/cxl/phb.c

@@ -20,7 +20,7 @@ bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu
 	 * in the virtual phb, we'll need a default context to attach them to.
 	 */
 	ctx = cxl_dev_context_init(dev);
-	if (!ctx)
+	if (IS_ERR(ctx))
 		return false;
 	dev->dev.archdata.cxl_ctx = ctx;