drm/msm/dsi: drop modeset sanity checks

Drop the overly defensive modeset sanity checks of function parameters
which have already been checked or used by the callers.

Reviewed-by: Dmitry Baryshkov <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>
Tested-by: Kuogee Hsieh <[e-mail]>
Reviewed-by: Kuogee Hsieh <[e-mail]>
Reviewed-by: Abhinav Kumar <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/502678/
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

drivers/gpu/drm/msm/dsi/dsi.c

···
 int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
 			 struct drm_encoder *encoder)
 {
-	struct msm_drm_private *priv;
+	struct msm_drm_private *priv = dev->dev_private;
 	int ret;
-
-	if (WARN_ON(!encoder) || WARN_ON(!msm_dsi) || WARN_ON(!dev))
-		return -EINVAL;
-
-	priv = dev->dev_private;
 
 	if (priv->num_bridges == ARRAY_SIZE(priv->bridges)) {
 		DRM_DEV_ERROR(dev->dev, "too many bridges\n");