lib/cpumask: reorganize cpumask_local_spread() logic

Now after moving all NUMA logic into sched_numa_find_nth_cpu(),
else-branch of cpumask_local_spread() is just a function call, and
we can simplify logic by using ternary operator.

While here, replace BUG() with WARN_ON().

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Peter Lafreniere <peter@n8pjl.ca>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

lib/cpumask.c

@@ -127,16 +127,12 @@ unsigned int cpumask_local_spread(unsigned int i, int node)
 	/* Wrap: we always want a cpu. */
 	i %= num_online_cpus();
 
-	if (node == NUMA_NO_NODE) {
-		cpu = cpumask_nth(i, cpu_online_mask);
-		if (cpu < nr_cpu_ids)
-			return cpu;
-	} else {
-		cpu = sched_numa_find_nth_cpu(cpu_online_mask, i, node);
-		if (cpu < nr_cpu_ids)
-			return cpu;
-	}
-	BUG();
+	cpu = (node == NUMA_NO_NODE) ?
+		cpumask_nth(i, cpu_online_mask) :
+		sched_numa_find_nth_cpu(cpu_online_mask, i, node);
+
+	WARN_ON(cpu >= nr_cpu_ids);
+	return cpu;
 }
 EXPORT_SYMBOL(cpumask_local_spread);