fix fwh_lock locking

Hi all,

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.

Thanks.

@@ -65,11 +65,12 @@
 		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;