[MTD] Initialize 'writesize'

Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org>
diff --git a/drivers/mtd/chips/map_absent.c b/drivers/mtd/chips/map_absent.c
index a611de9..ac01a94 100644
--- a/drivers/mtd/chips/map_absent.c
+++ b/drivers/mtd/chips/map_absent.c
@@ -64,7 +64,8 @@
 	mtd->write 	= map_absent_write;
 	mtd->sync 	= map_absent_sync;
 	mtd->flags 	= 0;
-	mtd->erasesize = PAGE_SIZE;
+	mtd->erasesize  = PAGE_SIZE;
+	mtd->writesize  = 1;
 
 	__module_get(THIS_MODULE);
 	return mtd;