nvme-core: make implicit seed truncation explicit

The nvme_user_io.slba field is 64 bits wide. That value is copied into the
32-bit bio_integrity_payload.bip_iter.bi_sector field. Make that truncation
explicit to avoid that Coverity complains about implicit truncation. See
also Coverity ID 1056486 on http://scan.coverity.com/projects/linux.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -1132,7 +1132,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 
 	return nvme_submit_user_cmd(ns->queue, &c,
 			(void __user *)(uintptr_t)io.addr, length,
-			metadata, meta_len, io.slba, NULL, 0);
+			metadata, meta_len, lower_32_bits(io.slba), NULL, 0);
 }
 
 static u32 nvme_known_admin_effects(u8 opcode)