crypto: caam/qi - fix warning in init_cgr()

Coverity warns about an
"Unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)"
when computing the congestion threshold value.

Even though it is highly unlikely for an overflow to happen,
use this as an opportunity to simplify the code.
Signed-off-by: NHoria Geantă <horia.geanta@nxp.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/qi.c

@@ -657,9 +657,8 @@ static int init_cgr(struct device *qidev)
 {
 	int ret;
 	struct qm_mcc_initcgr opts;
-	const u64 cpus = *(u64 *)qman_affine_cpus();
-	const int num_cpus = hweight64(cpus);
-	const u64 val = num_cpus * MAX_RSP_FQ_BACKLOG_PER_CPU;
+	const u64 val = (u64)cpumask_weight(qman_affine_cpus()) *
+			MAX_RSP_FQ_BACKLOG_PER_CPU;
 
 	ret = qman_alloc_cgrid(&qipriv.cgr.cgrid);
 	if (ret) {