[INET]: Shrink struct inet_ehash_bucket on 32 bits UP

No need to align struct inet_ehash_bucket on a 8 bytes boundary.

On 32 bits Uniprocessor, that's a waste of 4 bytes per struct (50 %)

On other platforms, the attribute is useless, natual alignement is already 8.

platform     | Size before | Size after patch
-------------+-------------+------------------
32 bits, UP  |         8   |     4
32 bits, SMP |         8   |     8
64 bits, UP  |         8   |     8
64 bits, SMP |        16   |    16

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>