dm: table use uninitialized_var

drivers/md/dm-table.c: In function 'dm_get_device':
drivers/md/dm-table.c:478: warning: 'dev' may be used uninitialized in this function

Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Alasdair G Kergon <[e-mail]>

drivers/md/dm-table.c

···
 			      int mode, struct dm_dev **result)
 {
 	int r;
-	dev_t dev;
+	dev_t uninitialized_var(dev);
 	struct dm_dev *dd;
 	unsigned int major, minor;