libxl: xc_domain_restore returns 0 on success, 1 on error

Fix restore_common to handle it this way.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/libxl/libxl_dom.c

@@ -260,7 +260,7 @@ int restore_common(libxl_ctx *ctx, uint32_t domid,
                              state->store_port, &state->store_mfn,
                              state->console_port, &state->console_mfn,
                              info->hvm, info->u.hvm.pae, 0);
-    if ( rc < 0 ) {
+    if ( rc ) {
         XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "restoring domain");
         return ERROR_FAIL;
     }