drivers: s390/cio: Fix compilation warning about const qualifiers

Update __ccwdev_check_busid() and __ccwgroupdev_check_busid() to use
"const" qualifiers to fix the compiler warning.
Reported-by: kbuild test robot <lkp@intel.com>
Cc: gregkh@linuxfoundation.org
Cc: devel@driverdev.osuosl.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/s390/cio/ccwgroup.c

@@ -610,7 +610,7 @@ EXPORT_SYMBOL(ccwgroup_driver_unregister);
 
 static int __ccwgroupdev_check_busid(struct device *dev, const void *id)
 {
-	char *bus_id = id;
+	const char *bus_id = id;
 
 	return (strcmp(bus_id, dev_name(dev)) == 0);
 }

drivers/s390/cio/device.c

@@ -1655,9 +1655,7 @@ EXPORT_SYMBOL_GPL(ccw_device_force_console);
 static int
 __ccwdev_check_busid(struct device *dev, const void *id)
 {
-	char *bus_id;
-
-	bus_id = id;
+	const char *bus_id = id;
 
 	return (strcmp(bus_id, dev_name(dev)) == 0);
 }