drm/nouveau: remove set but not used variable ‘pdev’ in nouveau_bios_init

Fix follow warning:
drivers/gpu/drm/nouveau/nouveau_bios.c:2086:18: warning: variable ‘pdev’ set but not used [-Wunused-but-set-variable]
  struct pci_dev *pdev;
                  ^~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210123013014.3815870-1-yebin10@huawei.com

drivers/gpu/drm/nouveau/nouveau_bios.c

@@ -2083,13 +2083,11 @@ nouveau_bios_init(struct drm_device *dev)
 {
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nvbios *bios = &drm->vbios;
-	struct pci_dev *pdev;
 	int ret;
 
 	/* only relevant for PCI devices */
 	if (!dev_is_pci(dev->dev))
 		return 0;
-	pdev = to_pci_dev(dev->dev);
 
 	if (!NVInitVBIOS(dev))
 		return -ENODEV;