seqlock,lockdep: Fix seqcount_latch_init()

seqlock,lockdep: Fix seqcount_latch_init()

[ Upstream commit 4817a52b306136c8b2b2271d8770401441e4cf79 ]

seqcount_init() must be a macro in order to preserve the static
variable that is used for the lockdep key. Don't then wrap it in an
inline function, which destroys that.

Luckily there aren't many users of this function, but fix it before it
becomes a problem.

Fixes: 80793c3471d9 ("seqlock: Introduce seqcount_latch_t")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YEeFEbNUVkZaXDp4@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>