glxcmds: Fix possible array out of bounds
Index may overflow an array.
https://qarmin.gitlab.io/-/xserver/-/jobs/527304880/artifacts/report/25.html#line-983
Fixes #1030 (closed).
Index may overflow an array.
https://qarmin.gitlab.io/-/xserver/-/jobs/527304880/artifacts/report/25.html#line-983
Fixes #1030 (closed).