[libata] Shuffle DRV_xxx in core and SiS drivers, to kill warnings

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/pata_sis.c b/drivers/ata/pata_sis.c
index 1c5219f..88ed2aa 100644
--- a/drivers/ata/pata_sis.c
+++ b/drivers/ata/pata_sis.c
@@ -34,6 +34,7 @@
 #include <linux/ata.h>
 #include "libata.h"
 
+#undef DRV_NAME		/* already defined in libata.h, for libata-core */
 #define DRV_NAME	"pata_sis"
 #define DRV_VERSION	"0.4.5"