firmware/sysfb: fix an error code in sysfb_init()

This error path accidentally returns success when it should preserve the
error code from sysfb_parent_dev().

Fixes: 4e754597 ("firmware/sysfb: Create firmware device only for enabled PCI devices")
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/aaaa2e13-849b-41a0-8186-25f3d2a16f86@moroto.mountain

drivers/firmware/sysfb.c

@@ -127,8 +127,10 @@ static __init int sysfb_init(void)
 	sysfb_apply_efi_quirks();
 
 	parent = sysfb_parent_dev(si);
-	if (IS_ERR(parent))
+	if (IS_ERR(parent)) {
+		ret = PTR_ERR(parent);
 		goto unlock_mutex;
+	}
 
 	/* try to create a simple-framebuffer device */
 	compatible = sysfb_parse_mode(si, &mode);