mtd: nand: fully initialize mtd_oob_ops

We're not initializing the ooblen field. Our users don't care, since
they check that oobbuf == NULL first, but it's good practice to zero
unused fields out.

We can drop the NULL initializations since we're memset()ing the whole
thing.

Noticed by Coverity, CID #200821, #200822

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 5488a7a..d4cec2f 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -386,7 +386,7 @@
 	uint8_t buf[2] = { 0, 0 };
 	int ret = 0, res, i = 0;
 
-	ops.datbuf = NULL;
+	memset(&ops, 0, sizeof(ops));
 	ops.oobbuf = buf;
 	ops.ooboffs = chip->badblockpos;
 	if (chip->options & NAND_BUSWIDTH_16) {
@@ -1716,9 +1716,9 @@
 	int ret;
 
 	nand_get_device(mtd, FL_READING);
+	memset(&ops, 0, sizeof(ops));
 	ops.len = len;
 	ops.datbuf = buf;
-	ops.oobbuf = NULL;
 	ops.mode = MTD_OPS_PLACE_OOB;
 	ret = nand_do_read_ops(mtd, from, &ops);
 	*retlen = ops.retlen;
@@ -2508,9 +2508,9 @@
 	/* Grab the device */
 	panic_nand_get_device(chip, mtd, FL_WRITING);
 
+	memset(&ops, 0, sizeof(ops));
 	ops.len = len;
 	ops.datbuf = (uint8_t *)buf;
-	ops.oobbuf = NULL;
 	ops.mode = MTD_OPS_PLACE_OOB;
 
 	ret = nand_do_write_ops(mtd, to, &ops);
@@ -2536,9 +2536,9 @@
 	int ret;
 
 	nand_get_device(mtd, FL_WRITING);
+	memset(&ops, 0, sizeof(ops));
 	ops.len = len;
 	ops.datbuf = (uint8_t *)buf;
-	ops.oobbuf = NULL;
 	ops.mode = MTD_OPS_PLACE_OOB;
 	ret = nand_do_write_ops(mtd, to, &ops);
 	*retlen = ops.retlen;