mtd: do not use plain 0 as NULL

The first 3 arguments of 'mtd_device_parse_register()' are pointers,
but many callers pass '0' instead of 'NULL'. Fix this globally. Thanks
to coccinelle for making it easy to do with the following semantic patch:

 @@
 expression mtd, types, parser_data, parts, nr_parts;
 @@
 (
 -mtd_device_parse_register(mtd, 0, parser_data, parts, nr_parts)
 +mtd_device_parse_register(mtd, NULL, parser_data, parts, nr_parts)
 |
 -mtd_device_parse_register(mtd, types, 0, parts, nr_parts)
 +mtd_device_parse_register(mtd, types, NULL, parts, nr_parts)
 |
 -mtd_device_parse_register(mtd, types, parser_data, 0, nr_parts)
 +mtd_device_parse_register(mtd, types, parser_data, NULL, nr_parts)
 )

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/cs553x_nand.c b/drivers/mtd/nand/cs553x_nand.c
index 414afa7..e2b7c9e 100644
--- a/drivers/mtd/nand/cs553x_nand.c
+++ b/drivers/mtd/nand/cs553x_nand.c
@@ -313,7 +313,7 @@
 	for (i = 0; i < NR_CS553X_CONTROLLERS; i++) {
 		if (cs553x_mtd[i]) {
 			/* If any devices registered, return success. Else the last error. */
-			mtd_device_parse_register(cs553x_mtd[i], NULL, 0,
+			mtd_device_parse_register(cs553x_mtd[i], NULL, NULL,
 						  NULL, 0);
 			err = 0;
 		}