crypto: hisilicon/qm - modify the return type of debugfs interface

Since 'qm_create_debugfs_file' always returns 0, change it as 'void'.

Signed-off-by: Weili Qian <qianweili@huawei.com>
Reviewed-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>