wifi: ath11k: wmi: use common error handling style

Also these functions don't follow the preferred style so fix those.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23

Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230609142440.24643-8-kvalo@kernel.org