soc: fsl: guts: machine variable might be unset

If both the model and the compatible properties are missing, then
machine will not be set. Initialize it with NULL.

Fixes: 34c1c21e ("soc: fsl: fix section mismatch build warnings")
Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/soc/fsl/guts.c

@@ -140,7 +140,7 @@ static int fsl_guts_probe(struct platform_device *pdev)
 	struct device_node *root, *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
 	const struct fsl_soc_die_attr *soc_die;
-	const char *machine;
+	const char *machine = NULL;
 	u32 svr;
 
 	/* Initialize guts */