more trivial signedness fixes in drivers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index e783e67..9ce4aa9 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1122,7 +1122,7 @@
 					 const struct piix_map_db *map_db)
 {
 	struct piix_host_priv *hpriv = pinfo[0].private_data;
-	const unsigned int *map;
+	const int *map;
 	int i, invalid_map = 0;
 	u8 map_value;