block: move CONFIG_BLOCK guard to top Makefile

block: move CONFIG_BLOCK guard to top Makefile

[ Upstream commit 4c928904ff771a8e830773b71a080047365324a5 ]

Every object under block/ depends on CONFIG_BLOCK.

Move the guard to the top Makefile since there is no point to
descend into block/ if CONFIG_BLOCK=n.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210927140000.866249-5-masahiroy@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 998b30c3948e ("io_uring: Fix a null-ptr-deref in io_tctx_exit_cb()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit d9e1e5d8a74c4bbe7595d0e21a733218190c3da7)
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>