Fix out of bounds memory read in apply_sao_internal

[sashashura]

This PR fixes out of bounds memory read in apply_sao_internal revealed by fuzzing kimageformats: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=31485

There are two issues:

1. saoOffsetVal is defined as int8_t saoOffsetVal[3][4];. When bandIdx is larger than 4 it leads to out of bounds memory read.
2. bandTable is defined as int bandTable[32]. When in_img[xC+i+(yC+j)*in_stride]>>bandShift results in > 31 it leads to out of bounds memory read.