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>

fs/ramfs/inode.c

@@ -266,12 +266,8 @@ static struct file_system_type ramfs_fs_type = {
 	.fs_flags	= FS_USERNS_MOUNT,
 };
 
-int __init init_ramfs_fs(void)
+static int __init init_ramfs_fs(void)
 {
-	static unsigned long once;
-
-	if (test_and_set_bit(0, &once))
-		return 0;
 	return register_filesystem(&ramfs_fs_type);
 }
 fs_initcall(init_ramfs_fs);

include/linux/ramfs.h

@@ -19,7 +19,6 @@ extern int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize);
 
 extern const struct file_operations ramfs_file_operations;
 extern const struct vm_operations_struct generic_file_vm_ops;
-extern int __init init_ramfs_fs(void);
 
 int ramfs_fill_super(struct super_block *sb, void *data, int silent);
 

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)