dm exception store: free tmp_store on persistent flag error

Error handling code following a kmalloc should free the allocated data.

Cc: stable@kernel.org
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

drivers/md/dm-exception-store.c

@@ -216,7 +216,8 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
 		type = get_type("N");
 	else {
 		ti->error = "Persistent flag is not P or N";
-		return -EINVAL;
+		r = -EINVAL;
+		goto bad_type;
 	}
 
 	if (!type) {