crypto: hisilicon/qm - delete redundant code

The "qdma" is a structure variable instead of actual data. This
structure doesn't need to be zerod, The memset is useless and redundant.
So delete it.

Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>