Merge branch 'rhashtable-bit-locking-m68k'

NeilBrown says:

====================
Fix rhashtable bit-locking for m68k

As reported by Guenter Roeck, the new rhashtable bit-locking
doesn't work on m68k as it only requires 2-byte alignment, so BIT(1)
is addresses is not unused.

We current use BIT(0) to identify a NULLS marker, but that is only
needed in ->next pointers.  The bucket head does not need a NULLS
marker, so the lsb there can be used for locking.

the first 4 patches make some small improvements and re-arrange some
code.  The final patch converts to using only BIT(0) for these two
different special purposes.

I had previously suggested dropping the series until I fix it.  Given
that this was fairly easy, I retract that I think it best simply to
add these patches to fix the code.
====================

Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>