xkb: Fix buffer overflow in _XkbSetCompatMap() #231

Job	Run time
Build on ubuntu:20.04 - clang	8m 21s
Build on ubuntu:22.04 - gcc	7m 23s
Build on ubuntu:22.04 - clang	8m 12s
Build on ubuntu:20.04 - gcc	8m 9s
Build on debian:stable - gcc	8m 8s
Build on quay.io/centos/centos:stream9 - clang	9m 13s
Build on debian:sid - gcc	7m 48s
Build on quay.io/rockylinux/rockylinux:8 - clang	9m 47s
Build on ubuntu:24.04 - gcc	7m 52s
Build on debian:stable - clang	8m 34s
Build on ubuntu:24.04 - clang	8m 54s
Build on fedora:latest - gcc	9m 30s
Build on fedora:latest - clang	8m 39s
Build on debian:sid - clang	8m 39s
Build on quay.io/rockylinux/rockylinux:8 - gcc	7m 56s
Build on quay.io/centos/centos:stream9 - gcc	8m 24s
	2h 15m 29s

Provide feedback