drm/i915/gvt: fix detect_host calling logic

Like other routines, intel_gvt_hypervisor_detect_host returns 0
for success.
Signed-off-by: NXiaoguang Chen <xiaoguang.chen@intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/gvt.c

@@ -65,6 +65,8 @@ struct intel_gvt_io_emulation_ops intel_gvt_io_emulation_ops = {
  */
 int intel_gvt_init_host(void)
 {
+	int ret;
+
 	if (intel_gvt_host.initialized)
 		return 0;
 
@@ -90,7 +92,8 @@ int intel_gvt_init_host(void)
 		return -EINVAL;
 
 	/* Try to detect if we're running in host instead of VM. */
-	if (!intel_gvt_hypervisor_detect_host())
+	ret = intel_gvt_hypervisor_detect_host();
+	if (ret)
 		return -ENODEV;
 
 	gvt_dbg_core("Running with hypervisor %s in host mode\n",