When computing the starting slot number for a hash page table group we used
to do this
hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we
really don't need to clear then separately.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>