crypto: hisilicon/qm - fix missing put dfx access

In function qm_cmd_write(), if function returns from
branch 'atomic_read(&qm->status.flags) == QM_STOP',
the got dfx access is forgotten to put.

Fixes: 607c191b ("crypto: hisilicon - support runtime PM for accelerator device")
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>