video: vesa_fb: Fix wrong return value check of pci_find_class()

When pci_find_class() fails to find a device, it returns -ENODEV.
But now we check the return value against -1. Fix it.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Acked-by: NSimon Glass <sjg@chromium.org>
Acked-by: NAnatolij Gustschin <agust@denx.de>

drivers/video/vesa_fb.c

@@ -34,7 +34,7 @@ void *video_hw_init(void)
 	}
 	if (vbe_get_video_info(gdev)) {
 		dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, 0);
-		if (dev == -1) {
+		if (dev < 0) {
 			printf("no card detected\n");
 			return NULL;
 		}