drm/vc4: remove unneeded variable: "ret"

remove unneeded variable: "ret".
Signed-off-by: Bernard Zhao <bernard@vivo.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210202122338.15351-1-bernard@vivo.com

drivers/gpu/drm/vc4/vc4_gem.c

@@ -1026,7 +1026,6 @@ int vc4_queue_seqno_cb(struct drm_device *dev,
 		       void (*func)(struct vc4_seqno_cb *cb))
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	int ret = 0;
 	unsigned long irqflags;
 
 	cb->func = func;
@@ -1041,7 +1040,7 @@ int vc4_queue_seqno_cb(struct drm_device *dev,
 	}
 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
 
-	return ret;
+	return 0;
 }
 
 /* Scheduled when any job has been completed, this walks the list of