The back port of commit c7305645 ("powerpc/64s: Convert
slb_miss_common to use RFI_TO_USER/KERNEL") missed a hunk needed to
restore cr6.

Fixes: 48cc95d4 ("powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>