ubifs: Fix some kernel-doc warnings in tnc.c

Fixes the following W=1 kernel build warning(s):

fs/ubifs/tnc.c:3479: warning: Excess function parameter 'inum' description in 'dbg_check_inode_size'
fs/ubifs/tnc.c:366: warning: Excess function parameter 'node' description in 'lnc_free'

@inum in 'dbg_check_inode_size' should be @inode, fix it.
@node in 'lnc_free' is not in use, Remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/tnc.c

@@ -360,7 +360,6 @@ static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr,
 /**
  * lnc_free - remove a leaf node from the leaf node cache.
  * @zbr: zbranch of leaf node
- * @node: leaf node
  */
 static void lnc_free(struct ubifs_zbranch *zbr)
 {
@@ -3466,7 +3465,7 @@ out_unlock:
 /**
  * dbg_check_inode_size - check if inode size is correct.
  * @c: UBIFS file-system description object
- * @inum: inode number
+ * @inode: inode to check
  * @size: inode size
  *
  * This function makes sure that the inode size (@size) is correct and it does