vircgroup: fix MinGW build

Broken by commit <901d2b9c>.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

src/util/vircgroup.c

@@ -4335,6 +4335,21 @@ virCgroupSetMemory(virCgroupPtr group ATTRIBUTE_UNUSED,
 }
 
 
+int
+virCgroupGetMemoryStat(virCgroupPtr group ATTRIBUTE_UNUSED,
+                       unsigned long long *cache ATTRIBUTE_UNUSED,
+                       unsigned long long *activeAnon ATTRIBUTE_UNUSED,
+                       unsigned long long *inactiveAnon ATTRIBUTE_UNUSED,
+                       unsigned long long *activeFile ATTRIBUTE_UNUSED,
+                       unsigned long long *inactiveFile ATTRIBUTE_UNUSED,
+                       unsigned long long *unevictable ATTRIBUTE_UNUSED)
+{
+    virReportSystemError(ENOSYS, "%s",
+                         _("Control groups not supported on this platform"));
+    return -1;
+}
+
+
 int
 virCgroupGetMemoryUsage(virCgroupPtr group ATTRIBUTE_UNUSED,
                         unsigned long *kb ATTRIBUTE_UNUSED)