init_rootfs(): don't bother with init_ramfs_fs()

the only thing done by the latter is making ramfs visible
to mount(2); we don't need it there - rootfs is separate
and, in fact, made visible to mount(2) in the same init_rootfs().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

init/do_mounts.c

@@ -658,8 +658,6 @@ int __init init_rootfs(void)
 		(!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
 		err = shmem_init();
 		is_tmpfs = true;
-	} else {
-		err = init_ramfs_fs();
 	}
 
 	if (err)