spi25_statusreg: Return defined value on failed RDSR

The interface of spi_read_status_register() is broken and can't return
errors. Let's not return random stack data at least.

Change-Id: I714b20001a5443bba665c2e0061ca14069777581
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/22017
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
diff --git a/spi25_statusreg.c b/spi25_statusreg.c
index 01a6862..05c7acf 100644
--- a/spi25_statusreg.c
+++ b/spi25_statusreg.c
@@ -117,8 +117,11 @@
 
 	/* Read Status Register */
 	ret = spi_send_command(flash, sizeof(cmd), sizeof(readarr), cmd, readarr);
-	if (ret)
+	if (ret) {
 		msg_cerr("RDSR failed!\n");
+		/* FIXME: We should propagate the error. */
+		return 0;
+	}
 
 	return readarr[0];
 }