RAS/AMD/ATL: Fix array overflow in get_logical_coh_st_fabric_id_mi300()

Check against ARRAY_SIZE() which is the number of elements instead of
sizeof() which is the number of bytes.

Fixes: 453f0ae7 ("RAS/AMD/ATL: Add MI300 support")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/279c8b5e-6c00-467a-9071-9c67926abea4@moroto.mountain