[libata] sata_via: kill uninit'd var warning

Reported and initial patch by Marin Mitov.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/sata_via.c b/drivers/ata/sata_via.c
index 98e8c50..bdd43c7 100644
--- a/drivers/ata/sata_via.c
+++ b/drivers/ata/sata_via.c
@@ -566,7 +566,7 @@
 	static int printed_version;
 	unsigned int i;
 	int rc;
-	struct ata_host *host;
+	struct ata_host *host = NULL;
 	int board_id = (int) ent->driver_data;
 	const unsigned *bar_sizes;