drm/radeon/radeon_device.c: move a dereference below a NULL test

If a NULL value is possible, the dereference should only occur after the
NULL test.

Coverity CID: 13335
Signed-off-by: Darren Jenkins <darrenrjenkins@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_device.c

@@ -733,16 +733,18 @@ void radeon_device_fini(struct radeon_device *rdev)
  */
 int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
 {
-	struct radeon_device *rdev = dev->dev_private;
+	struct radeon_device *rdev;
 	struct drm_crtc *crtc;
 	int r;
 
-	if (dev == NULL || rdev == NULL) {
+	if (dev == NULL || dev->dev_private == NULL) {
 		return -ENODEV;
 	}
 	if (state.event == PM_EVENT_PRETHAW) {
 		return 0;
 	}
+	rdev = dev->dev_private;
+
 	/* unpin the front buffers */
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		struct radeon_framebuffer *rfb = to_radeon_framebuffer(crtc->fb);