drm/komeda: Add check for komeda_get_layer_fourcc_list()

Add check for the return value of komeda_get_layer_fourcc_list()
to catch the potential exception.

Fixes: 5d51f6c0 ("drm/komeda: Add writeback support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://lore.kernel.org/r/20241219090256.146424-1-haoxiang_li2024@163.com


Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>