Fix compiler warning messages in LPGEMM code:
- Removed extraneous parentheses in aocl_batch_gemm_s8s8s32os32.c
- Removed unused variables in lpgemv_{m,n}_kernel_s8_grp_amd512vnni.c
- Changed ERR_UBOUND in math_utils_avx2.h and math_utils_avx512.h
to match how it is specified in AOCL libm erff.c
AMD-Internal: [CPUPL-6579]