ath10k: fix possible memory leak in ath10k_pci_probe()

memory is malloced in ath10k_pci_probe() and should be freed before
leaving from the error handling cases, otherwise it will cause
memory leak.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>