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 <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Suzuki K Poulose <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/s390/cio/ccwgroup.c

···
 
 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

···
 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);
 }