uacce: vma_close clears q->qfrs when freeing qfrs

vma_close frees qfrs but not clears q->qfrs, which still points
to the freed object, leading to subsequent mmap fail.
So vma_close clears q->qfrs as well.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Link: https://lore.kernel.org/r/20230511095921.9331-3-zhangfei.gao@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>