[EBTABLES]: Clean up vmalloc usage in net/bridge/netfilter/ebtables.c

Make all the vmalloc calls in net/bridge/netfilter/ebtables.c follow
the standard convention.  Remove unnecessary casts, and use '*object'
instead of 'type'.

Signed-off-by: Jayachandran C. <c.jayachandran@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>