drm/tegra: dsi: fix device leak on probe

[ Upstream commit bfef062 ]

Make sure to drop the reference taken when looking up the companion
(ganged) device and its driver data during probe().

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Fixes: e94236c ("drm/tegra: dsi: Add ganged mode support")
Fixes: 221e363 ("drm/tegra: Fix reference leak in tegra_dsi_ganged_probe")
Cc: stable@vger.kernel.org	# 3.19: 221e363
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20251121164201.13188-1-johan@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: jhovold

drivers/gpu/drm/tegra/dsi.c

@@ -1539,11 +1539,9 @@ static int tegra_dsi_ganged_probe(struct tegra_dsi *dsi)
 			return -EPROBE_DEFER;
 
 		dsi->slave = platform_get_drvdata(gangster);
-
-		if (!dsi->slave) {
-			put_device(&gangster->dev);
+		put_device(&gangster->dev);
+		if (!dsi->slave)
 			return -EPROBE_DEFER;
-		}
 
 		dsi->slave->master = dsi;
 	}