md/raid5-ppl: Use atomic64_inc_return() in ppl_new_iounit()

Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref)
to use optimized implementation and ease register pressure around
the primitive for targets that implement optimized variant.

Signed-off-by: Uros Bizjak <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Yu Kuai <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Reviewed-by: Artur Paszkiewicz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Song Liu <[email protected]>

Author: ubizjak

drivers/md/raid5-ppl.c

@@ -258,7 +258,7 @@ static struct ppl_io_unit *ppl_new_iounit(struct ppl_log *log,
 	memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
 	pplhdr->signature = cpu_to_le32(ppl_conf->signature);
 
-	io->seq = atomic64_add_return(1, &ppl_conf->seq);
+	io->seq = atomic64_inc_return(&ppl_conf->seq);
 	pplhdr->generation = cpu_to_le64(io->seq);
 
 	return io;