Use the previously unused S390_ARCH_FAC_MASK_SIZE_U64 instead of
S390_ARCH_FAC_LIST_SIZE_U64 for defining the fac_mask array.
Note that both values are the same, there is no functional change.
Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Signed-off-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx>