mtd: mark mtd_is_partition argument as constant

'struct mtd_info' is not modified by 'mtd_is_partition()' so it can be marked
as "const".

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h
index 2475228..02a5115 100644
--- a/include/linux/mtd/partitions.h
+++ b/include/linux/mtd/partitions.h
@@ -79,7 +79,7 @@
 extern int register_mtd_parser(struct mtd_part_parser *parser);
 extern int deregister_mtd_parser(struct mtd_part_parser *parser);
 
-int mtd_is_partition(struct mtd_info *mtd);
+int mtd_is_partition(const struct mtd_info *mtd);
 int mtd_add_partition(struct mtd_info *master, char *name,
 		      long long offset, long long length);
 int mtd_del_partition(struct mtd_info *master, int partno);