[PATCH] drm/nouveau/kms: Remove set but not used 'ret'

[Tian Tao]

This addresses the following gcc warning with "make W=1":
drivers/gpu/drm/nouveau/dispnv50/disp.c: In function ‘nv50_mstm_prepare’:
drivers/gpu/drm/nouveau/dispnv50/disp.c:1378:6: warning:
variable ‘ret’ set but not used [-Wunused-but-set-variable]

Signed-off-by: Tian Tao <tiantao6 at hisilicon.com>
---
 drivers/gpu/drm/nouveau/dispnv50/disp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index b111fe2..d05c57c 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1379,6 +1379,9 @@ nv50_mstm_prepare(struct nv50_mstm *mstm)
 
 	NV_ATOMIC(drm, "%s: mstm prepare\n", mstm->outp->base.base.name);
 	ret = drm_dp_update_payload_part1(&mstm->mgr);
+	if (ret) {
+                NV_ATOMIC(drm, "failed to update payload %d\n", ret);
+        }
 
 	drm_for_each_encoder(encoder, mstm->outp->base.base.dev) {
 		if (encoder->encoder_type == DRM_MODE_ENCODER_DPMST) {
-- 
2.7.4