vfs: correct the comments of vfs_*() helpers

correct the comments of vfs_*() helpers in fs/namei.c, including:
1. vfs_create()
2. vfs_mknod()
3. vfs_mkdir()
4. vfs_rmdir()
5. vfs_symlink()

All of them come from the same commit:
6521f891 "namei: prepare for idmapped mounts"

The @dentry is actually the dentry of child directory rather than
base directory(parent directory), and thus the @dir has to be
modified due to the change of @dentry.
Signed-off-by: Congjie Zhou <zcjie0802@qq.com>
Link: https://lore.kernel.org/r/tencent_2FCF6CC9E10DC8A27AE58A5A0FE4FCE96D0A@qq.comSigned-off-by: Christian Brauner <brauner@kernel.org>

fs/namei.c

@@ -3248,9 +3248,9 @@ static inline umode_t vfs_prepare_mode(struct mnt_idmap *idmap,
 /**
  * vfs_create - create new file
  * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of @dentry
- * @dentry:	pointer to dentry of the base directory
- * @mode:	mode of the new file
+ * @dir:	inode of the parent directory
+ * @dentry:	dentry of the child file
+ * @mode:	mode of the child file
  * @want_excl:	whether the file must not yet exist
  *
  * Create a new file.
@@ -4047,9 +4047,9 @@ EXPORT_SYMBOL(user_path_create);
 /**
  * vfs_mknod - create device node or file
  * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of @dentry
- * @dentry:	pointer to dentry of the base directory
- * @mode:	mode of the new device node or file
+ * @dir:	inode of the parent directory
+ * @dentry:	dentry of the child device node
+ * @mode:	mode of the child device node
  * @dev:	device number of device to create
  *
  * Create a device node or file.
@@ -4174,9 +4174,9 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d
 /**
  * vfs_mkdir - create directory
  * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of @dentry
- * @dentry:	pointer to dentry of the base directory
- * @mode:	mode of the new directory
+ * @dir:	inode of the parent directory
+ * @dentry:	dentry of the child directory
+ * @mode:	mode of the child directory
  *
  * Create a directory.
  *
@@ -4256,8 +4256,8 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
 /**
  * vfs_rmdir - remove directory
  * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of @dentry
- * @dentry:	pointer to dentry of the base directory
+ * @dir:	inode of the parent directory
+ * @dentry:	dentry of the child directory
  *
  * Remove a directory.
  *
@@ -4537,8 +4537,8 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname)
 /**
  * vfs_symlink - create symlink
  * @idmap:	idmap of the mount the inode was found from
- * @dir:	inode of @dentry
- * @dentry:	pointer to dentry of the base directory
+ * @dir:	inode of the parent directory
+ * @dentry:	dentry of the child symlink file
  * @oldname:	name of the file to link to
  *
  * Create a symlink.