connector: improved unaligned access error fix

In af3e095a

, Erik Jacobsen fixed one type of unaligned access
bug for ia64 by converting a 64-bit write to use put_unaligned().
Unfortunately, since gcc will convert a short memset() to a series
of appropriately-aligned stores, the problem is now visible again
on tilegx, where the memset that zeros out proc_event is converted
to three 64-bit stores, causing an unaligned access panic.

A better fix for the original problem is to ensure that proc_event
is aligned to 8 bytes here.  We can do that relatively easily by
arranging to start the struct cn_msg aligned to 8 bytes and then
offset by 4 bytes.  Doing so means that the immediately following
proc_event structure is then correctly aligned to 8 bytes.

The result is that the memset() stores are now aligned, and as an
added benefit, we can remove the put_unaligned() calls in the code.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: David S. Miller <davem@davemloft.net>