AVX512: Remove invalid error checking
AVX512: Remove invalid error checking

An offset-only memref can also have an opmask decorator.
e.g.) vmovdqu32 [0xabcd]{k1}, zmm0

Signed-off-by: Jin Kyu Song <636a629b48a15ad840070a3dd8c6df980563dd68@intel.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm