virsh: report error if vcpu number exceed the guest maxvcpu number

Commit id '81dd81e4' caused a regression when attempting to print a
specific vcpuid that is out of the range of the maximum vcpus for
the guest, such as:

 $ virsh vcpupin $dom 1000
 VCPU: CPU Affinity
 ----------------------------------

 $

Rather than just recover the old message, let's adjust the message based
on what would be displayed for a similar failure in the set path, such as:

 $ virsh vcpupin $dom 1000
 error: vcpu 1000 is out of range of persistent cpu count 2

 $ virsh vcpupin $dom 1000 --live
 error: vcpu 1000 is out of range of live cpu count 2

 $
Signed-off-by: NLuyao Huang <lhuang@redhat.com>

tools/virsh-domain.c

@@ -6497,6 +6497,20 @@ cmdVcpuPin(vshControl *ctl, const vshCmd *cmd)
             goto cleanup;
         }
 
+        if (got_vcpu && vcpu >= ncpus) {
+            if (flags & VIR_DOMAIN_AFFECT_LIVE ||
+                (flags & VIR_DOMAIN_AFFECT_CURRENT &&
+                 virDomainIsActive(dom) == 1))
+                vshError(ctl,
+                         _("vcpu %d is out of range of live cpu count %d"),
+                         vcpu, ncpus);
+            else
+                vshError(ctl,
+                         _("vcpu %d is out of range of persistent cpu count %d"),
+                         vcpu, ncpus);
+            goto cleanup;
+        }
+
         cpumaplen = VIR_CPU_MAPLEN(maxcpu);
         cpumap = vshMalloc(ctl, ncpus * cpumaplen);
         if ((ncpus = virDomainGetVcpuPinInfo(dom, ncpus, cpumap,