fix leak in romfs_fill_super()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index c117fa8..42d2135 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -544,6 +544,7 @@
 error_rsb_inval:
 	ret = -EINVAL;
 error_rsb:
+	kfree(rsb);
 	return ret;
 }