init: add an init_rmdir helper

Add a simple helper to rmdir with a kernel space file name and switch
the early init code over to it.  Remove the now unused ksys_rmdir.

Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/init.c

@@ -42,3 +42,8 @@ int __init init_unlink(const char *pathname)
 {
 	return do_unlinkat(AT_FDCWD, getname_kernel(pathname));
 }
+
+int __init init_rmdir(const char *pathname)
+{
+	return do_rmdir(AT_FDCWD, getname_kernel(pathname));
+}

include/linux/init_syscalls.h

@@ -4,3 +4,4 @@ int __init init_mount(const char *dev_name, const char *dir_name,
 		const char *type_page, unsigned long flags, void *data_page);
 int __init init_umount(const char *name, int flags);
 int __init init_unlink(const char *pathname);
+int __init init_rmdir(const char *pathname);

include/linux/syscalls.h

@@ -1273,13 +1273,6 @@ int compat_ksys_ipc(u32 call, int first, int second,
  * The following kernel syscall equivalents are just wrappers to fs-internal
  * functions. Therefore, provide stubs to be inlined at the callsites.
  */
-long do_rmdir(int dfd, struct filename *name);
-
-static inline long ksys_rmdir(const char __user *pathname)
-{
-	return do_rmdir(AT_FDCWD, getname(pathname));
-}
-
 extern long do_mkdirat(int dfd, const char __user *pathname, umode_t mode);
 
 static inline long ksys_mkdir(const char __user *pathname, umode_t mode)

init/initramfs.c

@@ -300,7 +300,7 @@ static void __init clean_path(char *path, umode_t fmode)
 
 	if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
 		if (S_ISDIR(st.mode))
-			ksys_rmdir(path);
+			init_rmdir(path);
 		else
 			init_unlink(path);
 	}