caam: Fix crash in case caam_jr_probe failed

If probing caam_jr returns failure, the variable "dev" will not be
initialized, so we can't use dev->name for the error print.
Otherwise it will cause crash.

Signed-off-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Gaurav Jain <gaurav.jain@nxp.com>
diff --git a/arch/arm/mach-imx/imx8/cpu.c b/arch/arm/mach-imx/imx8/cpu.c
index 0858ea5..936c8f8 100644
--- a/arch/arm/mach-imx/imx8/cpu.c
+++ b/arch/arm/mach-imx/imx8/cpu.c
@@ -100,7 +100,7 @@
 
 		ret = uclass_get_device_by_driver(UCLASS_MISC, DM_DRIVER_GET(caam_jr), &dev);
 		if (ret)
-			printf("Failed to initialize %s: %d\n", dev->name, ret);
+			printf("Failed to initialize caam_jr: %d\n", ret);
 	}
 
 	return 0;