[MTD] Fix fwh_lock locking

This is on a custom board with a mapping driver access to an ST
M50LPW080 chip. This chip is probed successfully with
do_map_probe("jedec_probe",...). If I use the mtdchar interface to
perform unlock->erase->program->lock on any of the 16 eraseblocks in the
chip, the chip is left in FL_STATUS mode while the data structures
believe that the chip is in FL_READY mode. Hence, any subsequent reads
to any flash byte results in 0x80 being read.
Signed-off-by: NShashi Rao <shashi@sun.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

drivers/mtd/chips/fwh_lock.h

@@ -65,11 +65,12 @@ static int fwh_xxlock_oneblock(struct map_info *map, struct flchip *chip,
 		return ret;
 	}
 
+	chip->oldstate = chip->state;
 	chip->state = xxlt->state;
 	map_write(map, CMD(xxlt->val), adr);
 
 	/* Done and happy. */
-	chip->state = FL_READY;
+	chip->state = chip->oldstate;
 	put_chip(map, chip, adr);
 	spin_unlock(chip->mutex);
 	return 0;