mesa: avoid triggering assert in implementation

mesa: avoid triggering assert in implementation

When tearing down a GL context with an active performance query, the
implementation can be confused by a query marked active when it's
being deleted.

This shouldn't happen in the implementation because the context will
already be idle.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: <mesa-stable@lists.freedesktop.org>
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/2235
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3115>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3115>