drm/display: bridge_connector: get/put the panel_bridge

drm/display: bridge_connector: get/put the panel_bridge

The panel_bridge pointer is taken inside the loop and used after the
loop. Being a local variable, use a cleanup action to ensure it is put on
return.

Based on the code structure the panel_bridge pointer might be assigned
during multiple loop iterations. Even though this is probably not possible
in the practice, ensure there is no reference leak by putting the reference
to the old value before overwriting with the new value.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> # db410c
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://patch.msgid.link/20251017-drm-bridge-alloc-getput-bridge-connector-fix-hdmi_cec-v2-3-667abf6d47c0@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>