CVE-2026-74367: wifi: ath12k: fix inconsistent arvif state in vdev_create error paths

In the Linux kernel, the following vulnerability has been resolved:

wifi: ath12k: fix inconsistent arvif state in vdevcreate error paths

ath12kmacvdevcreate() has three error path issues that leave arvif in an inconsistent state:

1. When ath12kwmivdevcreate() fails, the function returns directly without clearing arvif->ar, which was already set before the WMI call. Subsequent code checking arvif->ar to determine vdev readiness will see a non-NULL value despite no vdev existing in firmware.

2. When ath12kwmisendpeerdeletecmd() fails in errpeerdel, the code jumped to err: skipping the DP peer cleanup and vdev rollback, leaving numcreatedvdevs, vdev maps and arvif list membership live.

3. When ath12kwaitforpeerdeletedone() fails, the code jumped to errvdevdel: skipping the DP peer cleanup.

Fix by changing the ath12kwmivdevcreate() failure to goto err instead of returning directly, routing both errpeerdel failure paths through errdppeerdel: for proper DP peer and vdev rollback, and consolidating the arvif state cleanup at err:.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPLV1.0V2.0SILICONZ-1.115823.3