Compression level is too high for real-time compression

[urain39]

https://github.com/zeelog/android_kernel_xiaomi_mido/blob/fbc134ca3635ce5f65c1251cec7d6a7faf281b84/crypto/zstd.c#L25

In most cases, high compression levels require more time for compression, but the compression rate has not increased significantly (about 5%, for level 1 and level 5).

Also, considering that the performance of msm8953 is not very good, I think the best compression level is 1.