From: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
Now it's ready to move the mempool based SG chained allocator code from
SCSI driver to lib/sg_pool.c, which will be compiled only based on a Kconfig
symbol CONFIG_SG_POOL.
SCSI selects CONFIG_SG_POOL.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Ming Lin <ming.l@xxxxxxxxxxxxxxx>