Created by: lidanqing-intel

Removed the "conv_p != NULL" branch, Now the conv computeINT8 is similar and as clear as computeFP32.

INT8 and FP32 could be merged together because two functions are similar now. But to isolate possible bugs, maybe separating as now would be better.

Hi ! @wojtuss @kbinias @jczaja @Sand3r- @grygielski if you have time, please help review, Thanks !