crypto: hisilicon - avoid unused function warning

The only caller of hisi_zip_vf_q_assign() is hidden in an #ifdef,
so the function causes a warning when CONFIG_PCI_IOV is disabled:

drivers/crypto/hisilicon/zip/zip_main.c:740:12: error: unused function 'hisi_zip_vf_q_assign' [-Werror,-Wunused-function]

Replace the #ifdef with an IS_ENABLED() check that leads to the
function being dropped based on the configuration.

Fixes: 79e09f30 ("crypto: hisilicon - add SRIOV support for ZIP")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/hisilicon/zip/zip_main.c

@@ -785,7 +785,6 @@ static int hisi_zip_clear_vft_config(struct hisi_zip *hisi_zip)
 
 static int hisi_zip_sriov_enable(struct pci_dev *pdev, int max_vfs)
 {
-#ifdef CONFIG_PCI_IOV
 	struct hisi_zip *hisi_zip = pci_get_drvdata(pdev);
 	int pre_existing_vfs, num_vfs, ret;
 
@@ -815,9 +814,6 @@ static int hisi_zip_sriov_enable(struct pci_dev *pdev, int max_vfs)
 	}
 
 	return num_vfs;
-#else
-	return 0;
-#endif
 }
 
 static int hisi_zip_sriov_disable(struct pci_dev *pdev)
@@ -948,7 +944,8 @@ static struct pci_driver hisi_zip_pci_driver = {
 	.id_table		= hisi_zip_dev_ids,
 	.probe			= hisi_zip_probe,
 	.remove			= hisi_zip_remove,
-	.sriov_configure	= hisi_zip_sriov_configure,
+	.sriov_configure	= IS_ENABLED(CONFIG_PCI_IOV) ?
+					hisi_zip_sriov_configure : 0,
 	.err_handler		= &hisi_zip_err_handler,
 };