[PATCH] drm/panel: himax-hx83121a: Fix incorrect error check for devm_drm_panel_alloc()

[Chen Ni]

Check devm_drm_panel_alloc() return value for ERR_PTR instead of NULL.
devm_drm_panel_alloc() returns an ERR_PTR on failure, never NULL. Using
a NULL check skips the error path and may cause a NULL pointer
dereference.

Fixes: a7c61963b727 ("drm/panel: Add Himax HX83121A panel driver")
Signed-off-by: Chen Ni <nic...@iscas.ac.cn>
---
 drivers/gpu/drm/panel/panel-himax-hx83121a.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-himax-hx83121a.c 
b/drivers/gpu/drm/panel/panel-himax-hx83121a.c
index ebe643ba4184..bed79aa06f46 100644
--- a/drivers/gpu/drm/panel/panel-himax-hx83121a.c
+++ b/drivers/gpu/drm/panel/panel-himax-hx83121a.c
@@ -596,8 +596,8 @@ static int himax_probe(struct mipi_dsi_device *dsi)
 
        ctx = devm_drm_panel_alloc(dev, struct himax, panel, &himax_panel_funcs,
                                   DRM_MODE_CONNECTOR_DSI);
-       if (!ctx)
-               return -ENOMEM;
+       if (IS_ERR(ctx))
+               return PTR_ERR(ctx);
 
        ret = devm_regulator_bulk_get_const(&dsi->dev,
                                            ARRAY_SIZE(himax_supplies),
-- 
2.25.1