netlink: remove hash::nelems check in netlink_insert

[ Upstream commit 0041195d55bc38df6b574cc8c36dcf2266fbee39 ]

The type of hash::nelems has been changed from size_t to atom_t
which in fact is int, so not need to check if BITS_PER_LONG, that
is bit number of size_t, is bigger than 32

and rht_grow_above_max() will be called to check if hashtable is
too big, ensure it can not bigger than 1<<31

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: c1bb9484e3b0 ("netlink: annotate data races around nlk->portid")
Signed-off-by: Sasha Levin <sashal@kernel.org>