Revert "qemu: fix build when !HAVE_NUMACTL"

This reverts commit d8978c90.

Not suitable for -maint without backporting a feature as well,
according to Jim's post here:

http://www.mail-archive.com/libvir-list@redhat.com/msg57781.html

src/qemu/qemu_process.c

@@ -1735,8 +1735,7 @@ cleanup:
 }
 #else
 static int
-qemuProcessInitNumaMemoryPolicy(virDomainObjPtr vm,
-                                const char *nodemask ATTRIBUTE_UNUSED)
+qemuProcessInitNumaMemoryPolicy(virDomainObjPtr vm)
 {
     if (vm->def->numatune.memory.nodemask) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",