crypto: hisilicon/qm - cleanup warning in qm_vf_read_qos

The kernel test rebot report this warning: Uninitialized variable: ret.
The code flow may return value of ret directly. This value is an
uninitialized variable, here is fix it.
Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/hisilicon/qm.c

@@ -4295,7 +4295,7 @@ static void qm_vf_get_qos(struct hisi_qm *qm, u32 fun_num)
 static int qm_vf_read_qos(struct hisi_qm *qm)
 {
 	int cnt = 0;
-	int ret;
+	int ret = -EINVAL;
 
 	/* reset mailbox qos val */
 	qm->mb_qos = 0;