drm/msm/dp/dp_ctrl: Remove unneeded semicolon

fix semicolon.cocci warnings:
drivers/gpu/drm/msm/dp/dp_ctrl.c:1161:2-3: Unneeded semicolon
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dp/dp_ctrl.c

@@ -1158,7 +1158,7 @@ static int dp_ctrl_link_rate_down_shift(struct dp_ctrl_private *ctrl)
 	default:
 		ret = -EINVAL;
 		break;
-	};
+	}
 
 	if (!ret)
 		DRM_DEBUG_DP("new rate=0x%x\n", ctrl->link->link_params.rate);