vc4: Fix leak in HW queries error path

Reported by Coverity: in the case where there exist hardware and
non-hardware queries, the code does not jump to err_free_query and leaks
the query.

CID: 1430194
Signed-off-by: Ernestas Kulik <ernestas.kulik@gmail.com>
Fixes: 9ea90ffb ("broadcom/vc4: Add support for HW perfmon")
(cherry picked from commit f6e49d5a)