wifi: ath11k: fix memory leaks in beacon template setup

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

wifi: ath11k: fix memory leaks in beacon template setup

The functions ath11k_mac_setup_bcn_tmpl_ema() and ath11k_mac_setup_bcn_tmpl_mbssid() allocate memory for beacon templates but fail to free it when parameter setup returns an error.

Since beacon templates must be released during normal execution, they must also be released in the error handling paths to prevent memory leaks.

Fix this by using unified exit paths with proper cleanup in the respective error paths.

Compile tested only. Issue found using a prototype static analysis tool and code review.