fbdev: chipsfb: Fix error codes in chipsfb_pci_init()

The error codes are not set on these error paths.

Fixes: 145eed48 ("fbdev: Remove conflicting devices on PCI bus")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/Y/yG+sm2mhdJeTZW@kili