virsh: use correct sizeof when allocating cpumap

Found by coverity:
Error: SIZEOF_MISMATCH (CWE-569):
    libvirt-0.10.2/tools/virsh-domain.c:4754: suspicious_sizeof: Passing
    argument "8UL /* sizeof (cpumap) */" to function
    "_vshCalloc(vshControl *, size_t, size_t, char const *, int)" and
    then casting the return value to "unsigned char *" is suspicious.

Error: SIZEOF_MISMATCH (CWE-569):
    libvirt-0.10.2/tools/virsh-domain.c:4942: suspicious_sizeof: Passing
    argument "8UL /* sizeof (cpumap) */" to function
    "_vshCalloc(vshControl *, size_t, size_t, char const *, int)" and
    then casting the return value to "unsigned char *" is suspicious.

tools/virsh-domain.c

@@ -4768,7 +4768,7 @@ cmdVcpuPin(vshControl *ctl, const vshCmd *cmd)
 
     /* Pin mode: pinning specified vcpu to specified physical cpus*/
 
-    cpumap = vshCalloc(ctl, cpumaplen, sizeof(cpumap));
+    cpumap = vshCalloc(ctl, cpumaplen, sizeof(*cpumap));
     /* Parse cpulist */
     cur = cpulist;
     if (*cur == 0) {
@@ -4954,7 +4954,7 @@ cmdEmulatorPin(vshControl *ctl, const vshCmd *cmd)
 
     /* Pin mode: pinning emulator threads to specified physical cpus*/
 
-    cpumap = vshCalloc(ctl, cpumaplen, sizeof(cpumap));
+    cpumap = vshCalloc(ctl, cpumaplen, sizeof(*cpumap));
     /* Parse cpulist */
     cur = cpulist;
     if (*cur == 0) {