Convert obvious places to deactivate_locked_super()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index 92285d0..af8b42e 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -74,8 +74,7 @@
 
 	ret = fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
 	if (ret < 0) {
-		up_write(&sb->s_umount);
-		deactivate_super(sb);
+		deactivate_locked_super(sb);
 		return ret;
 	}