Fixed smlua_model_util_get_id buffer overflow

[Flower35]

• added the missing limit check for sCustomModelsCount
  • more than 256 custom models (for example: loading multiple Character Select Packs) caused memory overflow into bbh_seg7_vertex_
• changed LOG_ERROR to LOG_LUA_LINE in smlua_model_util_get_id()
  • the mod dev can easily see in-game any missing models
  • similar to getting warnings about missing audio files with audio_sample_load()