libxl: enable remote shutdown for pure hvm domain.

Signed-off-by: Zhigang Wang <zhigang.x.wang@xxxxxxxxxx>

diff -r 96917cf25bf3 tools/libxl/libxl.c
--- a/tools/libxl/libxl.c	Fri May 28 10:54:07 2010 +0100
+++ b/tools/libxl/libxl.c	Mon May 31 17:05:42 2010 +0800
@@ -550,7 +550,7 @@
     shutdown_path = libxl_sprintf(ctx, "%s/control/shutdown", dom_path);
 
     xs_write(ctx->xsh, XBT_NULL, shutdown_path, req_table[req], strlen(req_table[req]));
-    if (/* hvm */ 0) {
+    if (is_hvm(ctx, domid)) {
         unsigned long acpi_s_state = 0;
         unsigned long pvdriver = 0;
         xc_get_hvm_param(ctx->xch, domid, HVM_PARAM_ACPI_S_STATE, &acpi_s_state);