mtd: mtdchar: add missing initializer on raw write

On writes in MODE_RAW the mtd_oob_ops struct is not sufficiently
initialized which may cause nandwrite to fail. With this patch
it is possible to write raw nand/oob data without additional ECC
(either for testing or when some sectors need different oob layout
e.g. bootloader) like
nandwrite  -n -r -o  /dev/mtd0 <myfile>

Signed-off-by: Peter Wippich <pewi@gw-instruments.de>
Cc: stable@kernel.org
Tested-by: Ricard Wanderlof <ricardw@axis.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

drivers/mtd/mtdchar.c

@@ -320,6 +320,7 @@ static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count
 			ops.mode = MTD_OOB_RAW;
 			ops.datbuf = kbuf;
 			ops.oobbuf = NULL;
+			ops.ooboffs = 0;
 			ops.len = len;
 
 			ret = mtd->write_oob(mtd, *ppos, &ops);