Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with cpu_online()

A slight improvement in readability, and this does also remove one
memory access when NR_CPUS == 1! ;-)

Signed-off-by: Andrea Parri (Microsoft) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Michael Kelley <[e-mail]>
Signed-off-by: Wei Liu <[e-mail]>

drivers/hv/vmbus_drv.c

···
 	/* No CPUs should come up or down during this. */
 	cpus_read_lock();
 
-	if (!cpumask_test_cpu(target_cpu, cpu_online_mask)) {
+	if (!cpu_online(target_cpu)) {
 		cpus_read_unlock();
 		return -EINVAL;
 	}