wifi: ath10k: Fix return value in ath10k_pci_init()

This driver is attempting to register to support two different buses.
if either of these is successful then ath10k_pci_init() should return 0
so that hardware attached to the successful bus can be probed and
supported. only if both of these are unsuccessful should ath10k_pci_init()
return an errno.

Fixes: 0b523ced ("ath10k: add basic skeleton to support ahb")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20221110061926.18163-1-xiujianfeng@huawei.com