fix: avoid crash with LoRAs and type override

[wbruna]

Using a LoRA with e.g. --type q8_0 on Vulkan triggers:

ggml/src/ggml-vulkan/ggml-vulkan.cpp:6093: GGML_ASSERT(ggml_vk_dim01_contiguous(src1) || src1->type == GGML_TYPE_F32 || src1->type == GGML_TYPE_F16) failed