[MTD] Initialize 'writesize'

Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org>
diff --git a/drivers/mtd/devices/pmc551.c b/drivers/mtd/devices/pmc551.c
index 666cce1..f620d74 100644
--- a/drivers/mtd/devices/pmc551.c
+++ b/drivers/mtd/devices/pmc551.c
@@ -778,7 +778,8 @@
                 mtd->type 	= MTD_RAM;
                 mtd->name 	= "PMC551 RAM board";
                 mtd->erasesize 	= 0x10000;
-		mtd->owner = THIS_MODULE;
+                mtd->writesize  = 1;
+                mtd->owner = THIS_MODULE;
 
                 if (add_mtd_device(mtd)) {
                         printk(KERN_NOTICE "pmc551: Failed to register new device\n");