drm/bridge: samsung-dsim: samsung_dsim_host_attach: use a temporary variable for...

drm/bridge: samsung-dsim: samsung_dsim_host_attach: use a temporary variable for the next bridge

In preparation to handle refcounting of the out_bridge, we need to ensure
the out_bridge pointer contains either a valid bridge pointer or NULL, not
an ERR_PTR. Otherwise calls such as drm_bridge_get/put() would try to
redeference an ERR_PTR.

As a preliminary cleanup, add a temporary local 'next_bridge' pointer and
only copy it in dsi->out_bridge as late as possible, i.e. just before
calling pdata->host_ops->attach() which uses it (only in the exynos
driver).

Not strictly needed, but for symmetry move the clearing of dsi->out_bridge
in samsung_dsim_host_detach() to after pdata->host_ops->detach().

Acked-by: Maxime Ripard <mripard@kernel.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://patch.msgid.link/20260109-drm-bridge-alloc-getput-drm_of_find_bridge-2-v2-10-8bad3ef90b9f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>