ensure ip-adapter Ensure mask_h * mask_w equals sequence_length in `apply_effective_region_mask` function

[Suprhimp]

Hi,

I found that there is an error when I run ip-adapter with size 912x1144. which is one of the recommended pixel values for the generation of stable diffusion XL.

I think rounding to integer for mask_h and mask_w might cause the discrepancy.

I changed like below.

Thanks :)