drm/i915/gvt: Off by one in intel_vgpu_write_fence()

The > should be >= here so that we don't read one element beyond the
end of the array.

Fixes: 28a60dee2ce6 ("drm/i915/gvt: vGPU HW resource management")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

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

@@ -131,7 +131,7 @@ void intel_vgpu_write_fence(struct intel_vgpu *vgpu,
 
 	assert_rpm_wakelock_held(dev_priv);
 
-	if (WARN_ON(fence > vgpu_fence_sz(vgpu)))
+	if (WARN_ON(fence >= vgpu_fence_sz(vgpu)))
 		return;
 
 	reg = vgpu->fence.regs[fence];