ide: shorten timeout value in ide_driveid_update()

Shorten timeout value in ide_driveid_update() (30s -> 15s)
to match try_to_identify().

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 944cd85..59c0218 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -325,7 +325,7 @@
 
 	tp_ops->exec_command(hwif, ATA_CMD_ID_ATA);
 
-	if (ide_busy_sleep(hwif, WAIT_WORSTCASE, use_altstatus)) {
+	if (ide_busy_sleep(hwif, WAIT_WORSTCASE / 2, use_altstatus)) {
 		rc = 1;
 		goto out_err;
 	}