net: drop nopreempt requirement on sock_prot_inuse_add()

[ Upstream commit b3cb764a ]

This is distracting really, let's make this simpler,
because many callers had to take care of this
by themselves, even if on x86 this adds more
code than really needed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: a9bf9c7d ("af_unix: Annotate data-race of sk->sk_state in unix_stream_connect().")
Signed-off-by: Sasha Levin <sashal@kernel.org>